Display device

ABSTRACT

A display device is disclosed. The display device includes a substrate including a first area, a second area, and a first bending area located between the first and second areas. The first bending area is bent about a first bending axis extending in a first direction. The display device also includes a first inorganic insulating layer arranged over the substrate and having a first opening or a first groove at least in the first bending area, an organic material layer filling at least a part of the first opening or the first groove, and a first conductive layer extending from the first area to the second area across the first bending area and located over the organic material layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of co-pending U.S. patent applicationSer. No. 16/507,336, filed on Jul. 10, 2019, which is a Continuation ofU.S. patent application Ser. No. 15/404,057, filed on Jan. 11, 2017,which claims the benefit of Korean Patent Application No.10-2016-0016599, filed on Feb. 12, 2016, Korean Patent Application No.10-2016-0029690, filed on Mar. 11, 2016, and Korean Patent ApplicationNo. 10-2016-0042416, filed on Apr. 6, 2016 in the Korean IntellectualProperty Office, the disclosures of which are incorporated herein intheir entirety by reference.

BACKGROUND Field

The described technology generally relates to a display device.

Description of the Related Technology

In general, a display device includes a display unit on a substrate.Such a display device may be bent at least partially so as to improvevisibility from various angles or reduce an area of a non-displayregion.

However, defects may occur while manufacturing a display device that isbent, or a lifespan of the display device may be reduced.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

One inventive aspect relates to a display device that has a longerlifespan, and having fewer defects such as a disconnection duringmanufacturing processes thereof.

Another aspect is a display device that includes: a substrate includinga first area, a second area, and a first bending area located betweenthe first area and the second area, and the first bending area is bentabout a first bending axis extending in a first direction; a firstinorganic insulating layer arranged over the substrate and including afirst opening or a first groove corresponding to the first bending area;an organic material layer filling at least a part of the first openingor the first groove; and a first conductive layer extending from thefirst area to the second area across the first bending area, and locatedover the organic material layer.

The first opening or the first groove may overlap with the first bendingarea. An area of the first opening or the first groove may be greaterthan an area of the first bending area.

The display device may further include a protective film located over asurface of the substrate, wherein the surface may be opposite to thefirst inorganic insulating layer, and including an opening correspondingto the first bending area. An area of the opening may be greater than anarea of the first bending area. An area of the opening may be greaterthan an area of the first bending area and smaller than an area of thefirst opening or the first groove.

The organic material layer may cover an inner side surface of the firstopening or the first groove.

The organic material layer may include an uneven surface at leastpartially in an upper surface of the organic material layer. The organicmaterial layer may include the uneven surface only in the first openingor the first groove. An area of the uneven surface in the organicmaterial layer may be greater than an area of the first bending area,and smaller than an area of the first opening or the first groove.

The organic material layer may include a plurality of grooves extendingin the first direction in the upper surface of the organic materiallayer and defining the uneven surface.

An upper surface of the first conductive layer over the organic materiallayer may have a shape corresponding to a shape of the upper surface ofthe organic material layer.

The uneven surface may include a plurality of protrusions in a seconddirection that crosses the first direction, and a distance between theprotrusions at a center portion of the first opening or the first groovemay be less than a distance between the protrusions at other portions inthe first opening or the first groove.

The uneven surface may include a plurality of protrusions in a seconddirection that crosses the first direction, and a height from an uppersurface of the substrate to the protrusions at a center portion of thefirst opening or the first groove may be greater than a height from theupper surface of the substrate to the protrusions at other portions inthe first opening or the first groove.

The display device may further include a stress neutralization layerlocated over an upper portion of the first conductive layer, wherein anupper surface of the stress neutralization layer at least partially hasa shape corresponding to the uneven surface. The upper surface of thestress neutralization layer may have a same shape as that of the unevensurface. All of protrusions on the upper surface of the stressneutralization layer may correspond to at least some of the protrusionsin the uneven surface.

The organic material layer may include an uneven surface having aplurality of protrusions at least partially in an upper surface in asecond direction crossing the first direction, and a distance betweenthe protrusions at a portion adjacent to the inner side surface of thefirst opening or the first groove may be smaller than a distance betweenthe protrusions at other portions in the first opening or the firstgroove.

The organic material layer may include an uneven surface having aplurality of protrusions at least partially in an upper surface in asecond direction crossing the first direction, and a height from anupper surface of the substrate to the protrusions at a portion adjacentto the inner side surface of the first opening or the first groove maybe greater than a height from the upper surface of the substrate to theprotrusions at other portions in the first opening or the first groove.

The organic material layer may include a plurality of islands extendingin the first direction and spaced apart from one another in a seconddirection crossing the first direction.

An upper surface of the first conductive layer located over the islandsmay have a shape corresponding to shapes of upper surfaces of theislands.

A distance between the islands at a center portion of the first openingor the first groove may be smaller than a distance between the islandsat other portions in the first opening or the first groove.

A height from an upper surface of the substrate to the islands at acenter portion of the first opening or the first groove may be greaterthan a height from the upper surface of the substrate to the islands atother portions in the first opening or the first groove.

The display device may further include: a thin film transistor (TFT)arranged over the first area or the second area, and including a sourceelectrode, a drain electrode, and a gate electrode; an encapsulationlayer covering a display device over the first area; and a touchelectrode for a touch sensing layer located over the encapsulationlayer, wherein the first conductive layer may include a same material asthat of the touch electrode.

The display device may further include a touch protective layer coveringthe touch electrode and the first conductive layer.

The display device may further include an encapsulation layer includinga first inorganic encapsulation layer, a second inorganic encapsulationlayer, and an organic encapsulation layer arranged between the firstinorganic encapsulation layer and the second inorganic encapsulationlayer, the encapsulation layer being configured to cover a displaydevice over the first area, wherein the organic material layer mayinclude a same material as that of the organic encapsulation layer.

The display device may further include a second conductive layerarranged over the first area or the second area and located on a layerdifferent from a layer on which the first conductive layer is located,and the second conductive layer may be electrically connected to thefirst conductive layer.

An elongation rate of the first conductive layer may be greater than anelongation rate of the second conductive layer.

The display device may further include a TFT arranged over the firstarea or the second area, and comprising a source electrode, a drainelectrode, and a gate electrode, wherein the first conductive layer maybe located on a same layer as the source electrode and the drainelectrode, and the second conductive layer may be located on a samelayer as the gate electrode.

The TFT may further include a semiconductor layer, and the firstinorganic insulating layer may be arranged between the semiconductorlayer and the gate electrode.

The first inorganic insulating layer may be arranged between the TFT andthe substrate. The TFT may further include a semiconductor layer, andthe organic material layer may extend to be arranged between thesemiconductor layer and the gate electrode.

The display device may further include: a TFT arranged over the firstarea or the second area, and including a source electrode, a drainelectrode, and a gate electrode; and a planarization layer covering theTFT and including an organic material, wherein the organic materiallayer may include a same material as that of the planarization layer.

The organic material layer may be integrally formed with the interlayerinsulating layer.

The display device may further include: a first TFT arranged over thefirst area or the second area, and including a first semiconductorlayer, a first source electrode, a first drain electrode, and a firstgate electrode; and a second TFT arranged over the first area or thesecond area, and including a second semiconductor layer, a second sourceelectrode, a second drain electrode, and a second gate electrode,wherein a distance between a layer in which the first gate electrode islocated and the substrate may be smaller than a distance between a layerin which the second gate electrode is located and the substrate, thefirst inorganic insulating layer may be arranged between the firstsemiconductor layer and the first gate electrode and between the secondsemiconductor layer and the second gate electrode, and the organicmaterial layer may extend to be arranged between the first inorganicinsulating layer and the second gate electrode. The display device mayfurther include a second inorganic insulating layer arranged over theorganic material layer and including a second opening or a second groovecorresponding to the first bending area.

The display device may further include a second conductive layerarranged over the first area or the second area, including a samematerial as that of the first gate electrode, and electrically connectedto the first conductive layer, wherein the first conductive layer mayinclude a same material as that of the second gate electrode.

The substrate may include a second bending area that extends in a seconddirection crossing the first direction within the first area, and thesecond bending area may be bent about a second bending axis extending inthe second direction.

The substrate may have a chamfered corner that is closest to a pointwhere the first bending axis and the second bending axis cross eachother.

A radius of curvature at the first bending area may be smaller than aradius of curvature at the second bending area. The first inorganicinsulating layer may be continuous over at least a region including thesecond bending area within the first area.

Another aspect is a display device comprising: a substrate comprising afirst area, a second area, and a first bending area located between thefirst and second areas, wherein the first bending area is bent about afirst bending axis extending in a first direction; a first inorganicinsulating layer arranged over the substrate and having a first openingor a first groove at least in the first bending area; an organicmaterial layer filling at least a part of the first opening or the firstgroove; and a first conductive layer extending from the first area tothe second area across the first bending area and located over theorganic material layer.

In the above display device, the first opening or the first grooveoverlaps the first bending area.

In the above display device, first opening or the first groove has anarea that is greater than the first bending area.

The above display device further comprises a protective film locatedover a surface of the substrate, wherein the surface is opposite to thefirst inorganic insulating layer, and wherein the protective film has aprotective film opening at least in the first bending area.

In the above display device, the protective film opening has an areathat is greater than the first bending area.

In the above display device, the protective film opening has an areathat is greater than the first bending area and smaller than an area ofthe first opening or the first groove.

In the above display device, the organic material layer covers an innerside surface of the first opening or the first groove.

In the above display device, the organic material layer comprises anupper surface that is at least partially uneven.

In the above display device, the uneven portion of the organic materiallayer is disposed only in the first opening or the first groove.

In the above display device, the uneven portion of the organic materiallayer has an area is greater than the first bending area and smallerthan that of the first opening or the first groove.

In the above display device, the upper surface of the organic materiallayer comprises a plurality of grooves extending in the first direction,and wherein the grooves define the uneven portion.

In the above display device, an upper surface of the first conductivelayer has a shape corresponding to that of the upper surface of theorganic material layer.

In the above display device, the uneven portion comprises a plurality ofprotrusions in a second direction that crosses the first direction,wherein the protrusions at a center portion of the first opening or thefirst groove has a distance therebetween that is less than that betweenthe protrusions at other portions in the first opening or the firstgroove.

In the above display device, the uneven portion comprises a plurality ofprotrusions in a second direction that crosses the first direction, andwherein a height from an upper surface of the substrate to theprotrusions at a center portion of the first opening or the first grooveis greater than a height from the upper surface of the substrate to theprotrusions at other portions in the first opening or the first groove.

The display device of claim 8, further comprising a stressneutralization layer located over an upper portion of the firstconductive layer, wherein an upper surface of the stress neutralizationlayer at least partially has a shape corresponding to the unevenportion.

In the above display device, the upper surface of the stressneutralization layer has the same shape as that of the uneven portion.

In the above display device, all of the protrusions on the upper surfaceof the stress neutralization layer correspond to at least some of theprotrusions in the uneven portion.

In the above display device, the organic material layer comprises anuneven surface having a plurality of protrusions in a second directioncrossing the first direction, wherein a distance between the protrusionsat a portion adjacent to the inner side surface of the first opening orthe first groove is smaller than a distance between the protrusions atother portions in the first opening or the first groove.

In the above display device, the organic material layer comprises anuneven surface having a plurality of protrusions in a second directioncrossing the first direction, and wherein a height from an upper surfaceof the substrate to the protrusions at a portion adjacent to the innerside surface of the first opening or the first groove is greater than aheight from the upper surface of the substrate to the protrusions atother portions in the first opening or the first groove.

In the above display device, the organic material layer comprises aplurality of islands extending in the first direction and spaced apartfrom one another in a second direction crossing the first direction.

In the above display device, an upper surface of the first conductivelayer located over the islands has a shape corresponding to the islands.

In the above display device, a distance between the islands at a centerportion of the first opening or the first groove is smaller than adistance between the islands at other portions in the first opening orthe first groove.

In the above display device, a height from an upper surface of thesubstrate to the islands at a center portion of the first opening or thefirst groove is greater than a height from the upper surface of thesubstrate to the islands at other portions in the first opening or thefirst groove.

The above display device further comprises: a thin film transistor (TFT)arranged over the first area or the second area and comprising a sourceelectrode, a drain electrode, and a gate electrode; an encapsulationlayer covering an organic light-emitting diode (OLED) over the firstarea; and a touch electrode of a touch sensing layer located over theencapsulation layer, wherein the first conductive layer and the touchelectrode are formed of at least one same material.

The above display device further comprises a touch protective layercovering the touch electrode and the first conductive layer.

The above display device further comprises an additional OLED over thesecond area, wherein the encapsulation layer covers the additional OLEDover the second area.

The above display device further comprises an encapsulation layercomprising a first inorganic encapsulation layer, a second inorganicencapsulation layer, and an organic encapsulation layer arranged betweenthe first and second inorganic encapsulation layers, wherein theencapsulation layer covers a display device over the first area, andwherein the organic material layer and the organic encapsulation layerare formed of at least one same material.

The above display device further comprises a second conductive layerarranged over the first area or the second area and located on a layerdifferent from a layer on which the first conductive layer is located,wherein the second conductive layer is electrically connected to thefirst conductive layer.

In the above display device, an elongation rate of the first conductivelayer is greater than that of the second conductive layer.

The above display device further comprises a TFT arranged over the firstarea or the second area and comprising a source electrode, a drainelectrode, and a gate electrode, wherein the first conductive layer islocated on the same layer as the source and drain electrodes, andwherein the second conductive layer is located on the same layer as thegate electrode.

In the above display device, the TFT further comprises a semiconductorlayer, wherein the first inorganic insulating layer is arranged betweenthe semiconductor layer and the gate electrode.

In the above display device, the first inorganic insulating layer isarranged between the TFT and the substrate.

In the above display device, the TFT further comprises a semiconductorlayer, wherein the organic material layer extends to be interposedbetween the semiconductor layer and the gate electrode.

The above display device further comprises: a TFT arranged over thefirst area or the second area and comprising a source electrode, a drainelectrode, and a gate electrode; and a planarization layer covering theTFT and formed of an organic material, wherein the organic materiallayer and the planarization layer are formed of at least one samematerial.

The above display device further comprises: a TFT arranged over thefirst area or the second area and comprising a source electrode, a drainelectrode, and a gate electrode; and an interlayer insulating layerarranged between the source electrode and the gate electrode and betweenthe drain electrode and the gate electrode, wherein the organic materiallayer and the interlayer insulating layer are formed of at least onesame material.

In the above display device, the organic material layer is integrallyformed with the interlayer insulating layer.

The above display device further comprises: a first TFT arranged overthe first area or the second area and comprising a first semiconductorlayer, a first source electrode, a first drain electrode, and a firstgate electrode; and a second TFT arranged over the first area or thesecond area and comprising a second semiconductor layer, a second sourceelectrode, a second drain electrode, and a second gate electrode,wherein a distance between a layer in which the first gate electrode islocated and the substrate is smaller than a distance between a layer inwhich the second gate electrode is located and the substrate, whereinthe first inorganic insulating layer is arranged between the firstsemiconductor layer and the first gate electrode and between the secondsemiconductor layer and the second gate electrode, and wherein theorganic material layer extends to be interposed between the firstinorganic insulating layer and the second gate electrode.

The above display device further comprises a second inorganic insulatinglayer arranged over the organic material layer and comprising a secondopening or a second groove corresponding to the first bending area.

The above display device further comprises a second conductive layerarranged over the first area or the second area, wherein the secondconductive layer and the first gate electrode are formed of at least onesame material, wherein the second conductive layer is electricallyconnected to the first conductive layer, and wherein the firstconductive layer and the second gate electrode are formed of at leastone same material.

In the above display device, the substrate comprises a second bendingarea that extends in a second direction crossing the first directionwithin the first area, and wherein the second bending area is bent abouta second bending axis extending in the second direction.

In the above display device, the substrate has a chamfered corner thatis the closest to a point where the first bending axis and the secondbending axis cross each other.

In the above display device, a radius of curvature at the first bendingarea is smaller than that of the second bending area.

In the above display device, the first inorganic insulating layer iscontinuous over at least a region including the second bending areawithin the first area.

The above display device further comprises an additional inorganicinsulating layer comprising an additional opening corresponding to thefirst bending area and overlapping the first conductive layer.

In the above display device, the additional opening overlaps the firstbending area.

In the above display device, the additional opening has an area that isgreater than that of the first bending area.

In the above display device, the first opening or the first grooveoverlaps the first bending area.

In the above display device, the first opening or the first groove isgreater than an area of the first bending area.

In the above display device, the additional opening has an area that isgreater than that of the first opening or the first groove.

In the above display device, the additional opening corresponds to thefirst conductive layer within the first bending area.

In the above display device, the additional opening overlaps the firstconductive layer within the first bending area.

In the above display device, the additional opening has an area that isgreater than that of an upper surface of the first conductive layerwithin the first bending area.

In the above display device, the additional inorganic insulating layerat least partially covers an upper surface of the organic material layeron an outer portion of the first conductive layer within the firstbending area.

Another aspect is a display device that includes: a substrate comprisinga first area, a second area, and a first bent area located between thefirst and second areas, wherein the first bent area is bent about afirst bending axis extending in a first direction; a first inorganicinsulating layer arranged over the substrate and having a first openingor a first groove at least in the first bent area; an organic materiallayer filling at least a part of the first opening or the first groove;and a first conductive layer extending from the first area to the secondarea across the first bent area and located over the organic materiallayer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view partially showing a displaydevice according to an embodiment.

FIG. 2 is a schematic cross-sectional view partially showing the displaydevice of FIG. 1.

FIG. 3 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 4 is a schematic cross-sectional view partially showing a displaydevice according to a comparative example.

FIG. 5 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 6 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 7 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 8 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 9 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 10 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 11 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 12 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIGS. 13, 14 and 15 are schematic cross-sectional views illustratingprocesses of manufacturing the display device of FIG. 12.

FIG. 16 is a schematic cross-sectional view illustrating processes ofmanufacturing the display device of FIG. 12.

FIG. 17 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 18 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 19 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 20 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 21 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 22 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 23 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 24 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 25 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 26 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 27 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 28 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 29 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 30 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 31 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 32 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 33 is a schematic cross-sectional view of the display device ofFIG. 32 taken along a first bending axis in a first bending region.

FIG. 34 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 35 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 36 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 37 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 38 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 39 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 40 is a schematic cross-sectional view partially showing a displaydevice according to an embodiment.

FIG. 41 is a schematic plan view partially showing a display deviceaccording to an embodiment.

FIG. 42 is a schematic plan view partially showing a display deviceaccording to an embodiment.

FIG. 43 is a schematic perspective view partially showing a displaydevice according to an embodiment.

FIG. 44 is a schematic plan view partially showing the display device ofFIG. 43.

FIG. 45 is a schematic perspective view partially showing a displaydevice according to an embodiment.

FIG. 46 is a schematic perspective view partially showing a displaydevice according to an embodiment.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout. In this regard, the presentembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are merely described below, by referring to the figures, toexplain aspects of the present description. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. Expressions such as “at least one of,” whenpreceding a list of elements, modify the entire list of elements and donot modify the individual elements of the list.

Hereinafter, the described technology will be described in detail byexplaining preferred embodiments with reference to the attacheddrawings. Like reference numerals in the drawings denote like elements.

Sizes of components in the drawings may be exaggerated for convenienceof explanation. In other words, since sizes and thicknesses ofcomponents in the drawings are arbitrarily illustrated for convenienceof explanation, the following embodiments are not limited thereto.

In the following examples, the x-axis, the y-axis and the z-axis are notlimited to three axes of the rectangular coordinate system, and may beinterpreted in a broader sense. For example, the x-axis, the y-axis, andthe z-axis may be perpendicular to one another, or may representdifferent directions that are not perpendicular to one another. In thisdisclosure, the term “substantially” includes the meanings ofcompletely, almost completely or to any significant degree under someapplications and in accordance with those skilled in the art. Moreover,“formed, disposed or positioned over” can also mean “formed, disposed orpositioned on.” The term “connected” includes an electrical connection.

FIG. 1 is a schematic perspective view partially showing a displaydevice according to an embodiment, and FIG. 2 is a schematiccross-sectional view partially showing the display device of FIG. 1. Inthe display device, a substrate 100 that is a part of the display deviceis partially bent as shown in FIG. 1, and thus, the display device isalso bent due to the bent substrate 100. However, FIG. 2 shows thedisplay device that is not bent for convenience of description. Othercross-sectional views and plan views according to one or moreembodiments that will be described later also show display devices thatare not bent, for convenience of description.

As shown in FIGS. 1 and 2, the substrate 100 included in the displaydevice includes a first bending area BA extending in a first direction(+y direction). The first bending area BA is located between a firstarea 1A and a second area 2A, in a second direction (+x direction)crossing the first direction. In addition, as shown in FIG. 1, thesubstrate 100 is bent about a first bending axis 1BAX extending in thefirst direction (+y direction). The substrate 100 may include variousmaterials having flexible or bendable characteristics, e.g., a polymerresin such as polyethersulphone (PES), polyacrylate (PAR),polyetherimide (PEI), polyethyelenen napthalate (PEN),polyethyeleneterepthalate (PET), polyphenylene sulfide (PPS),polyallylate, polyimide (PI), polycarbonate (PC), and cellulose acetatepropionate (CAP).

The first area 1A includes a display area DA. As shown in FIG. 2, thefirst area 1A may include a part of a non-display area on an outerportion of the display area DA, as well as the display area DA. Thesecond area 2A also includes the non-display area. The second area 2Amay also include an additional display area (not shown), if necessary.

In addition to a display device 300, a thin film transistor (TFT) 210 towhich the display device 300 is electrically connected may be located onthe display area DA of the substrate 100, as shown in FIG. 2. In FIG. 2,an organic light-emitting diode (OLED) is located on the display area DAas the display device 300. If the second area 2A includes the additionaldisplay area, an OLED may be located on the additional display area.Such above electrical connection of the OLED to the TFT 210 may denotethat a pixel electrode 310 is electrically connected to the TFT 210. Ifnecessary, a TFT (not shown) may be arranged on a peripheral areaoutside the display area DA of the substrate 100. The TFT located on theperipheral area may be a part of, for example, a circuit unit forcontrolling electric signals applied to the display area DA.

The TFT 210 may include a semiconductor layer 211 including amorphoussilicon, polycrystalline silicon, or an organic semiconductor material,a gate electrode 213, a source electrode 215 a, and a drain electrode215 b. In order to ensure an insulating property between thesemiconductor layer 211 and the gate electrode 213, a gate insulatinglayer 120 formed of an inorganic material such as silicon oxide, siliconnitride, and/or silicon oxynitride may be interposed between thesemiconductor layer 211 and the gate electrode 213. In addition, aninterlayer insulating layer 130 formed of an inorganic material such assilicon oxide, silicon nitride, and/or silicon oxynitride may bearranged on the gate electrode 213, and the source electrode 215 a andthe drain electrode 215 b may be arranged on the interlayer insulatinglayer 130. As described above, the insulating layer including theinorganic material may be formed in a chemical vapor deposition (CVD) oran atomic layer deposition (ALD) method. This is applied to one or moreembodiments and modified examples thereof that will be described later,as well.

A buffer layer 110 formed of an inorganic material such as siliconoxide, silicon nitride, and/or silicon oxynitride may be arrangedbetween the TFT 210 having the above structure and the substrate 100.The buffer layer 110 may improve smoothness of an upper surface of thesubstrate 100, or may prevent or reduce infiltration of impurities intothe semiconductor layer 211 of the TFT 210.

In addition, a planarization layer 410 may be arranged on the TFT 210.For example, an OLED is arranged on the TFT 210 as shown in FIG. 2, theplanarization layer 140 may planarize an upper portion of a protectivelayer that covers the TFT 210. The planarization layer 140 may be formedof an organic material, for example, benzocyclobutene (BCB) orhexamethyldisiloxane (HMDSO). In FIG. 2, the planarization layer 140 hasa single-layered structure, but the planarization layer 140 may have amulti-layered structure. In addition, as shown in FIG. 2, theplanarization layer 140 may have an opening on an outer portion of thedisplay area DA so that a part of the planarization layer 140 on thedisplay area DA and a part of the planarization layer 140 on the secondarea 2A may be physically separate. Thus, the impurities from outsidemay not infiltrate into the display area DA across the planarizationlayer 140.

In the display area DA of the substrate 100, an OLED including a pixelelectrode 310, an opposite electrode 320, and an intermediate layer 330including an emission layer and arranged between the pixel electrode 310and the opposite electrode 320 may be located on the planarization layer140. The pixel electrode 310 is electrically connected to the TFT 210 bycontacting one of the source electrode 215 a and the drain electrode 215b via an opening formed in the planarization layer 140, as shown in FIG.2.

A pixel defining layer 150 may be arranged on the planarization layer140. The pixel defining layer 150 having an opening corresponding toeach of sub-pixels, that is, an opening exposing at least a centerportion of the pixel electrode 310, to define pixels. Also, in theexample of FIG. 2, the pixel defining layer 150 increases a distancebetween an edge of the pixel electrode 310 and the opposite electrode330 above the pixel electrode 310 to prevent arc from generating at theedge of the pixel electrode 310. The pixel defining layer 150 mayinclude, for example, an organic material such as polyimide orhexamethyldisiloxane (HMDSO).

The intermediate layer 320 of the OLED may be formed of low-molecularweight organic materials or polymer organic materials. When theintermediate layer 320 is formed of a low-molecular organic material,the emission layer 242 may include a hole injection layer (HIL), a holetransport layer (HTL), an emission layer (EML), an electron transportlayer (ETL), and an electron injection layer (EIL) in a single ormultiple-layered structure, and examples of organic materials mayinclude copper phthalocyanine (CuPc),N,N′-Di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB), andtris-8-hydroxyquinoline aluminum (Alq₃). The low-molecular weightorganic materials may be deposited by a vacuum deposition method.

When the intermediate layer 320 is formed of a polymer material, theintermediate layer 320 may include a hole transport layer (HTL) and anemission layer (EML). Here, the HTL may include PEDOT, and the EML mayinclude a poly-phenylenevinylene (PPV)-based or polyfluorene-basedpolymer material. Such above intermediate layer 320 may be formed by ascreen printing method, an inkjet printing method, or a laser inducedthermal imaging (LITI) method.

The intermediate layer 320 is not limited to the above example, but mayhave various structures. In addition, the intermediate layer 320 mayinclude a layer that is integrally formed throughout a plurality ofpixel electrodes 310, or a layer that is patterned to correspond to eachof the pixel electrodes 310.

The opposite electrode 330 is arranged above the display area DA, and asshown in FIG. 2, may cover the display area DA. That is, the oppositeelectrode 330 may be integrally formed with respect to a plurality ofOLEDs, so as to correspond to a plurality of pixel electrodes 310.

Since the OLED may easily be damaged by external moisture or oxygen, anencapsulation layer 400 may cover the OLED to protect the OLED. Theencapsulation layer 400 covers the display area DA, and then may extendto outside the display area DA. The encapsulation layer 400 may includea first inorganic encapsulation layer 410, an organic encapsulationlayer 420, and a second inorganic encapsulation 430 as shown in FIG. 2.

The first inorganic encapsulation layer 410 covers the oppositeelectrode 330, and may include silicon oxide, silicon nitride, and/orsilicon oxynitride. If necessary, other layers such as a capping layermay be arranged between the first inorganic encapsulation layer 410 andthe opposite electrode 330. Since the first inorganic encapsulationlayer 410 is formed according to a structure arranged thereunder, thefirst inorganic encapsulation layer 410 may have an uneven uppersurface. The organic encapsulation layer 420 covers the first inorganicencapsulation layer 410, and unlike the first inorganic encapsulationlayer 410, the organic encapsulation layer 420 may have an even uppersurface. For example, the organic encapsulation layer 420 may have aroughly even upper surface at a portion corresponding to the displayarea DA. The organic encapsulation layer 420 may include at least onematerial including polyethylene terephthalate, polyethylene naphthalate,polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene,polyarylate, and hexamethyldisiloxane. The second inorganicencapsulation layer 430 covers the organic encapsulation layer 420, andmay include silicon oxide, silicon nitride, and/or silicon oxynitride.The second inorganic encapsulation layer 430 may contact the firstinorganic encapsulation layer 410 by an edge thereof at an outer portionof the display area DA, in order not to expose the organic encapsulationlayer 420 to outside.

As described above, since the encapsulation layer 400 includes the firstinorganic encapsulation layer 410, the organic encapsulation layer 420,and the second inorganic encapsulation layer 430, even if there is acrack in the encapsulation layer 400 in the above multi-layeredstructure, the crack may be disconnected between the first inorganicencapsulation layer 410 and the organic encapsulation layer 420 orbetween the organic encapsulation layer 420 and the second inorganicencapsulation layer 430. As such, forming of a path through which theexternal moisture or oxygen may infiltrated into the display area DA maybe prevented or reduced.

A polarization plate 520 may be located on the encapsulation layer 400by an optically clear adhesive (OCA) 510. The polarization plate 520 mayreduce reflection of external light. For example, when the externallight passed through the polarization plate 520 is reflected by an uppersurface of the opposite electrode 330 and then passes through thepolarization plate 520 again, the external light passes through thepolarization plate 520 twice and a phase of the external light may bechanged. Therefore, a phase of reflected light is different from thephase of the external light entering the polarization plate 520 so thata destructive interference occurs, and accordingly, reflection of theexternal light may be reduced and visibility may be improved. The OCA510 and the polarization plate 520 may cover the opening in theplanarization layer 140 as shown in FIG. 2. The display device accordingto the embodiment may not essentially include the polarization plate520, and if necessary, the polarization plate 520 may be omitted orreplaced with another component. For example, the polarization plate 520may be omitted, and instead, a black matrix and a color filter may beused to reduce the reflection of external light.

In addition, the buffer layer 110, the gate insulating layer 120, andthe interlayer insulating layer 130 including the inorganic material maybe referred to as a first inorganic insulating layer. The firstinorganic insulating layer may include a first opening corresponding toa first bending area 1BA, as shown in FIG. 2. That is, the buffer layer110, the gate insulating layer 120, and the interlayer insulating layer130 may respectively include openings 110 a, 120 a, and 130 acorresponding to the first bending area 1BA. That the first openingcorresponds to the first bending area 1BA may denote that the firstopening overlaps with the first bending area 1BA. Here, an area of thefirst opening may be greater than that of the first bending area 1BA. Todo this, in FIG. 2, a width OW of the first opening is greater than thatof the first bending area 1BA. Here, the area of the first opening maybe defined as an area of one having the smallest area, from among theopenings 110 a, 120 a, and 130 a of the buffer layer 110, the gateinsulating layer 120, and the interlayer insulating layer 130. Inaddition, in FIG. 2, the area of the first opening is described to bedefined by an area of the opening 110 a in the buffer layer 110.

In FIG. 2, an internal surface of the opening 110 a of the buffer layer110 and an internal surface of the opening 120 a in the gate insulatinglayer 120 are described to be equal to each other, but one or moreembodiments are not limited thereto. For example, as shown in FIG. 3that is a schematic cross-sectional view of a part of the display deviceaccording to another embodiment, an area of the opening 120 a of thegate insulating layer 120 may be greater than that of the opening 110 ain the buffer layer 110. In this case, the area of the first opening maybe also defined as an area of the opening having the smallest area, fromamong the openings 110 a, 120 a, and 130 a of the buffer layer 110, thegate insulating layer 120, and the interlayer insulating layer 130.

The display device may include an organic material layer 160 that fillsat least a part of the first opening of the first inorganic insulatinglayer. In FIG. 2, the organic material layer 160 fills the first openingentirely. In addition, the display device may include a first conductivelayer 215 c that extends from the first area 1A toward the second area2A through the first bending area 1BA to be located on the organicmaterial layer 160. The first conductive layer 215 c may be located onthe inorganic insulating layer such as the interlayer insulating layer130 where the organic material layer 160 does not exist. The firstconductive layer 215 c may be formed simultaneously, or concurrently,with the source electrode 215 a or the drain electrode 215 b by usingthe same material as that of the source electrode 215 a or the drainelectrode 215 b.

As described above, although FIG. 2 shows that the display device is notbent for convenience of description, the display device is in actuallyin a state in which the substrate 100 is bent at the first bending area1BA. To do this, the display device is manufactured so that thesubstrate 100 is flat as shown in FIG. 2, and then, the substrate 100 isbent at the first bending area 1BA so that the display device may havethe shape as shown in FIG. 1. Here, a tensile stress may be applied tothe first conductive layer 215 c while the substrate 100 is bent at thefirst bending area 1BA, but the display device may prevent or reduce theoccurrence of defects in the first conductive layer 215 c during thebending process.

If the first inorganic insulating layer including the buffer layer 110,the gate insulating layer 120, and/or the interlayer insulating layer130 does not include an opening at the first bending area 1BA, but isformed continuously from the first area 1A to the second area 2A, and ifthe first conductive layer 215 c is located on the first inorganicinsulating layer, a large tensile stress is applied to the firstconductive layer 215 c when the substrate 100 is bent. For example, thefirst inorganic insulating layer has a higher hardness than that of theorganic material layer, cracks are more likely to occur in the firstinorganic insulating layer at the first bending area 1BA, and if thecrack occurs in the first inorganic insulating layer, the firstconductive layer 215 c on the first inorganic insulating layer may alsohave the crack, and thus, there is a high possibility of generating adefect such as a disconnection in the first conductive layer 215 c.

However, according to the display device of the embodiment, the firstinorganic insulating layer has the first opening at the first bendingarea 1BA as described above, and the part of the first conductive layer215 c, which corresponds to the first bending area 1BA, is located onthe organic material layer 160 that fills at least a part of the firstinorganic insulating layer. Since the first inorganic insulating layerhas the first opening at the first bending area 1BA, a possibility ofgenerating a crack in the first inorganic insulating layer is very low,and the organic material layer 160 has a low possibility of generatingthe crack due to the organic material included in the organic materiallayer 160. Therefore, occurrence of the crack in the part of the firstconductive layer 215 c may be prevented or reduced, wherein the part ofthe first conductive layer 215 c corresponds to the first bending area1BA and is located on the organic material layer 160. Since the organicmaterial layer 160 has a hardness that is lower than that of theinorganic material layer, the tensile stress generating due to thebending of the substrate 100 may be absorbed by the organic materiallayer 160 so that concentration of the tensile stress onto the firstconductive layer 215 c may be effectively reduced.

The display device may include second conductive layers 213 a and 213 b,in addition to the first conductive layer 215 c. The second conductivelayers 213 a and 213 b may be arranged on the first area 1A or thesecond area 2A to be located at different layer level from that of thefirst conductive layer 215 c, and may be electrically connected to thefirst conductive layer 215 c. In FIG. 2, the second conductive layers213 a and 213 b are located at the same layer level as the gateelectrode 213 of the TFT 210, that is, on the gate insulating layer 120,and include the same material as the gate electrode 213. In addition,the first conductive layer 215 c contacts the second conductive layers213 a and 213 b via contact holes formed in the interlayer insulatinglayer 130. In addition, the second conductive layer 213 a is located onthe first area 1A and the second conductive layer 213 b is located onthe second area 2A.

The second conductive layer 213 a located on the first area 1A may beelectrically connected to the TFT in the display area DA, andaccordingly, the first conductive layer 215 c may be electricallyconnected to the TFT in the display area DA via the second conductivelayer 213 a. The second conductive layer 213 b located on the secondarea 2A may be electrically connected to the TFT in the display area DAvia the first conductive layer 215 c, as well. As described above, thesecond conductive layers 213 a and 213 b located on the outer portion ofthe display area DA may be electrically connected to components locatedin the display area DA, or may extend toward the display area DA so asto be located at least partially in the display area DA.

As described above, FIG. 2 shows the display device that is not bent forconvenience of description, but the display device is in a state inwhich the substrate 100 is actually bent at the first bending area 1BAas shown in FIG. 1. To do this, the display device is manufactured in astate where the substrate 100 is flat as shown in FIG. 2, and afterthat, the substrate 100 may be bent at the first bending area 1BA sothat the display device may have the shape as shown in FIG. 1. Here,while the substrate 100 is bent at the first bending area 1BA, tensilestress may be applied to components located within the first bendingarea 1BA.

Therefore, the first conductive layer 215 c that extends across thefirst bending area 1BA may include a material having a high strain rate,and thus, occurrence of crack in the first conductive layer 215 c or adefect such as a disconnection in the first conductive layer 215 c maybe prevented. In addition, the second conductive layers 213 a and 213 bmay include a material having a lower strain rate than that of the firstconductive layer 215 c and electrical/physical characteristics fromthose of the first conductive layer 215 c on the first area 1A or thesecond area 2A, and thus, an efficiency of transferring electricalsignals in the display device may be improved or a defect rate duringthe manufacturing processes may be reduced. For example, the secondconductive layers 213 a and 213 b may include molybdenum, and the firstconductive layer 215 c may include aluminum. The first conductive layer215 c and the second conductive layers 213 a and 213 b may includemulti-layered structures, if necessary.

Unlike the example shown in FIG. 2, an upper surface of the secondconductive layer 213 b located on the second area 2A may not be at leastpartially covered by the planarization layer 140 but exposed to outside,so as to be electrically connected to various electronic devices orprinted circuit boards.

As shown in FIG. 2, the organic material layer 160 may cover an internalsurface of the first opening in the first inorganic insulating layer. Asdescribed above, since the first conductive layer 215 c may have thesame material as those of the source and drain electrodes 215 a and 215b and may be formed simultaneously with the source and drain electrodes215 a and 215 b, and to do this, a conductive layer may be formed on anentire surface of the substrate 100 and patterned to form the sourceelectrode 215 a, the drain electrode 215 b, and the first conductivelayer 215 c. If the organic material layer 160 does not cover theinternal surface of the opening 110 a in the buffer layer 110, theinternal surface of the opening 120 a in the gate insulating layer 120,or the internal surface of the opening 130 a in the interlayerinsulating layer 130, a conductive material may not be removed, but mayremain on the internal surface of the opening 110 a in the buffer layer110, the internal surface of the opening 120 a in the gate insulatinglayer 120, or the internal surface of the opening 130 a in theinterlayer insulating layer 130 during patterning the conductive layer.In this case, the conductive material remaining on the internal layermay cause electric short with other conductive layers.

Therefore, when the organic material layer 160 is formed, the organicmaterial layer 160 may cover the internal surface of the first openingin the first inorganic insulating layer. In FIG. 2, the organic materiallayer 160 is described to have a constant thickness, but the organicmaterial layer 160 may have a thickness that varies depending onlocations, so that the organic material layer 160 may have an uppersurface having a gentle inclination around the internal surface of theopening 110 a of the buffer layer 110, the internal surface of theopening 120 a of the gate insulating layer 120, or the internal surfaceof the opening 130 a in the interlayer insulating layer 130.Accordingly, when the conductive layer is patterned in order to form thesource electrode 215 a, the drain electrode 215 b, and the firstconductive layer 215 c, remaining of the conductive material that shouldbe removed may be prevented effectively.

In addition, the organic material layer 160 may have an uneven surface160 a on at least partial upper surface in a +z direction, as shown inFIG. 2. Since the organic material layer 160 includes the uneven surface160 a, the first conductive layer 215 c located on the organic materiallayer 160 may have an upper surface and/or a lower surface having ashape corresponding to the uneven surface 160 a of the organic materiallayer 160.

As described above, since the tensile stress may be applied to the firstconductive layer 215 c when the substrate 100 is bent at the firstbending area 1BA in the manufacturing processes, when the upper surfaceand/or the lower surface of the first conductive layer 215 c has theshape corresponding to the uneven surface 160 a of the organic materiallayer 160, an amount of the tensile stress applied to the firstconductive layer 215 c may be reduced. That is, the tensile stressgenerated during the bending process may be reduced via deformation ofthe shape of the organic material layer 160 having a smaller hardness.Here, the first conductive layer 215 c having the uneven shape at leastbefore the bending process may be transformed to correspond to the shapeof the organic material layer 160, which is deformed due to the bendingprocess, and thus, occurrence of the defect such as the disconnection inthe first conductive layer 215 c may be prevented.

Also, the uneven surface 160 a is formed at least partially on the uppersurface of the organic material layer 160 (in the +z direction), asurface area of the upper surface of the organic material layer 160 anda surface area of the upper and lower surfaces of the first conductivelayer 215 c in the first opening may be increased. A large surface areaon the upper surface of the organic material layer 160 and the upper andlower surfaces of the first conductive layer 215 c may denote that adeformation margin is large in order to reduce the tensile stress causeddue to the bending of the substrate 100.

Since the first conductive layer 215 c is located on the organicmaterial layer 160, the lower surface of the first conductive layer 215c has a shape corresponding to the uneven surface 160 a of the organicmaterial layer 160. However, the upper surface of the first conductivelayer 215 c may have an uneven surface that is independent from theshape of the uneven surface 160 a of the organic material layer 160.

For example, after forming a conductive material layer on the organicmaterial layer 160, photoresist is applied on the conductive materiallayer and the photoresist is developed while varying an exposure amountaccording to locations on the photoresist by using a slit mask or ahalf-tone mask. Accordingly, the conductive material layer exposed dueto the developing of the photoresist is etched and then the photoresistis removed, and then, the first conductive layer 215 c is formed. Sincethe exposure amount varies depending on the locations on the photoresistby using the slit mask or the half-tone mask, a degree of etching theconductive material layer may vary depending on locations on theconductive material layer. Therefore, an uneven surface may beartificially formed on the upper surface of the first conductive layer215 c, and in this case, the upper surface of the first conductive layer215 c may have the uneven surface that is independent from the unevensurface 160 a of the organic material layer 160. This will be applied toone or more embodiments and modified examples thereof that will bedescribed later. Even if the process of artificially forming the unevensurface on the upper surface of the first conductive layer 215 c isperformed as described above, the uneven surface on the upper surface ofthe first conductive layer 215 c may correspond to the uneven surface160 a of the organic material layer 160.

The uneven surface 160 a on the upper surface 160 (in the +z direction)may be formed in various ways. For example, a photoresist material isused when the organic material layer 160 is formed, and an exposureamount varies depending on locations on the organic material layer 160,the upper surface of which is flat, by using a slit mask or a half-tonemask so that a certain part may be etched (removed) more than otherparts. Here, the part that is etched more may be a depressed portion inthe upper surface of the organic material layer 160. The method usedwhen manufacturing the display device according to the embodiment is notlimited to the above example. For example, after forming the organicmaterial layer 160 having the flat upper surface, certain portions areremoved by a dry etching method, and other various methods may be used.

In order for the organic material layer 160 to have the uneven surface160 a on the upper surface (in the +z direction), the organic materiallayer 160 may include a plurality of grooves in the upper surface (inthe +z direction), wherein the grooves extend in a first direction (+ydirection). Here, the shape of the upper surface of the first conductivelayer 215 c on the organic material layer 160 corresponds to the shapeof the upper surface of the organic material layer 160.

The organic material layer 160 may have the uneven surface 160 a onlywithin the first opening of the first inorganic insulating layer. InFIG. 2, a width UEW of the uneven surface 160 a of the organic materiallayer 160 is smaller than a width OW of the first opening of the firstinorganic insulating layer. If the organic material layer 160 has theuneven surface 160 a throughout the inside and outside the first openingin the first inorganic insulating layer, the organic material layer 160has the uneven surface 160 a near the internal surface of the opening110 a in the buffer layer 110, the internal surface of the opening 120 ain the gate insulating layer 120, or the internal surface of the opening130 a in the interlayer insulating layer 130.

In this case, as shown in FIG. 4 showing a part of a display deviceaccording to a comparative example, the organic material layer 160 has arelatively smaller thickness on depressed portions than that onprotruding portions, and thus, when the depressed portions are locatedaround the internal surface of the opening 110 a in the buffer layer110, the internal surface of the opening 120 in the gate insulatinglayer 120, or the internal surface of the opening 130 a in theinterlayer insulating layer 130, the organic material layer 160 may bedisconnected. Therefore, the organic material layer 160 may only havethe uneven surface 160 a within the first opening of the first inorganicinsulating layer, the disconnection of the organic material layer 160around the internal surface of the opening 110 a in the buffer layer110, the internal surface of the opening 120 a of the gate insulatinglayer 120, or the internal surface of the opening 130 a in theinterlayer insulating layer 130 may be prevented.

As described above, in order not to generate the disconnection in thefirst conductive layer 215 c at the first bending area 1BA, the organicmaterial layer 160 may have the uneven surface 160 a on the firstbending area 1BA. Therefore, an area of the uneven surface 160 a of theorganic material layer 160 may be greater than that of the first bendingarea 1BA and smaller than that of the first opening. That is, as shownin FIG. 2, the width UEW of the uneven surface 160 a of the organicmaterial layer 160 is greater than the width of the first bending area1BA and smaller than the width OW of the first opening.

In addition, as shown in FIG. 6 showing a part of a display deviceaccording to an embodiment, even if the organic material layer 160 hasthe uneven surface 160 a throughout the inside and outside the firstopening of the first inorganic insulating layer, the protruding portionsin the organic material layer 160 may be located around the internalsurface of the opening 110 a in the buffer layer 110, the internalsurface of the opening 120 in the gate insulating layer 120, or theinternal surface of the opening 130 a in the interlayer insulating layer130. In this case, since the protruding portions of the organic materiallayer 160 are relatively thicker than the depressed portions of theorganic material layer 160, the disconnection of the organic materiallayer 160 around the internal surface of the opening 110 a in the bufferlayer 110, the internal surface of the opening 120 in the gateinsulating layer 120, or the internal surface of the opening 130 a inthe interlayer insulating layer 130 may be prevented.

In addition, a stress neutralization layer (SNL) 600 may be located onan outer portion of the display area DA. That is, the SNL 600 may belocated over the first conductive layer 215 c to correspond to at leastthe first bending area 1BA.

When a stack structure is bent, there is a stress neutral plane in thestack structure. If there is no SNL 600, when the substrate 100 is bent,an excessive tensile stress may be applied to the first conductive layer215 c in the first bending area 1BA, because the location of the firstconductive layer 215 c may not correspond to a stress neutral plane.However, by forming the SNL 600 and adjusting a thickness and a modulusof the SNL 600, a location of the stress neutral plane in the structureincluding the substrate 100, the first conductive layer 215 c, and theSNL 600 may be adjusted. Therefore, the stress neutral plane may beadjusted to be located around the first conductive layer 215 c via theSNL 600, and thus, the tensile stress applied to the first conductivelayer 215 c may be reduced.

The SNL 600 may extend to an end of the substrate 100 in the displaydevice, unlike the example of FIG. 2. For example, in the second area2A, the first conductive layer 215 c, the second conductive layer 213 b,and/or other conductive layers electrically connected to the first andsecond conductive layers are not covered at least partially by theinterlayer insulating layer 130 or the planarization layer 140, but areelectrically connected to various electronic devices or printed circuitboards. Accordingly, the first conductive layer 215 c, the secondconductive layer 213 b, and/or the other conductive layers electricallyconnected to the first and second conductive layers may have portionsthat are electrically connected to the various electronic devices or theprinted circuit boards. Here, the electrically connected portions needto be protected against external impurities such as moist, and thus, theSNL 600 may cover the electrically connected portions so as to performas a protective layer as well. To do this, the SNL 600 may extend to,for example, the end of the substrate 100 of the display device.

In addition, in FIG. 2, an upper surface of the SNL 600 in a directiontoward the display area DA (−x direction) coincides with an uppersurface of the polarization plate 520 (in +z direction), but one or moreembodiments are not limited thereto. For example, an end of the SNL 600in the display area DA direction (−x direction) may partially cover anupper surface at the edge of the polarization plate 520. Otherwise, theend of the SNL 600 in the display area DA direction (−x direction) maynot contact the polarization plate 520 and/or a light transmittingadhesive 510. In the latter case, during or after forming the SNL 600,degradation of a display device such as an OLED due to gas generatedfrom the SNL 600 and moving toward the display area DA (−x direction)may be prevented.

As shown in FIG. 2, if the upper surface of the SNL 600 in a directiontoward the display area DA (−x direction) coincides with the uppersurface of the polarization plate 520 in the +z direction, if the end ofthe SNL 600 in the display area DA direction (−x direction) partiallycovers the upper surface at the end of the polarization plate 520, or ifthe end of the SNL 600 in the display area DA direction (−x direction)contacts the light transmitting adhesive 510, a thickness of the SNL 600corresponding to the display area DA (−x direction) may be greater thanthat of the other portions in the SNL 600. Since a liquid phase materialor a paste-type material may be applied and hardened to form the SNL600, a volume of the SNL 600 may be reduced through the hardeningprocess. Here, if the portion of the SNL 600 corresponding to thedisplay area DA (−x direction) is in contact with the polarization plate520 and/or the light-transmitting adhesive 510, the portion of the SNL600 is fixed at the location, and thus, a volume reduction occurs inremaining portion of the SN 600. Therefore, the thickness of the SNL 600corresponding to the display area DA (−x direction) may be greater thanthat of the other portion in the SNL 600.

FIG. 6 is a schematic cross-sectional view showing a part of a displaydevice according to an embodiment, and for example, around the firstopening in the first inorganic insulating layer. In the display device,the uneven surface 160 a of the organic material layer 160 have aplurality of protrusions in a second direction (+x direction) thatcrosses the first direction (+y direction), as described above. Here, adistance dl between two adjacent protrusions from among the protrusionsat the center portion of the first opening is less than a distance d2between two adjacent protrusions from among the protrusions on the otherportion in the first opening.

As described above with reference to FIG. 1, the substrate 100 of thedisplay device is bent about the first bending axis 1BAX extending inthe first direction (+y direction). Accordingly, the substrate 100, theorganic material layer 160, and the first conductive layer 215 c arebent at the first bending area 1BA, and at this time, the largesttensile stress may be applied to the first conductive layer 215 c at thecenter portion of the first bending area 1BA, that is, at the centerportion of the first opening. Therefore, by reducing the distance d1between the protrusions at the center portion of the first opening to besmaller than the distance d2 between the protrusions at the otherportion in the first opening, the surface area of the upper surface onthe organic material layer 160 at the center portion of the firstopening and the surface area of the upper and lower surfaces of thefirst conductive layer 215 c at the center portion of the first openingmay be relatively greater than that of the other portion in the firstopening. The large surface area on the upper surface of the organicmaterial layer 160 and the upper and lower surfaces of the firstconductive layer 215 c may denote a large deformation margin forreducing the tensile stress caused by the bending of the substrate 100.Here, a point where the distance d1 between the protrusions is changedto the distance d2 may be located within the first bending area 1BA.

In other portion of the first opening than the center portion or theportion adjacent to the edge in the first opening, the distance betweenthe adjacent protrusions may be different from the distance d1 or thedistance d2. Moreover, the distance between the adjacent protrusionsfrom among the protrusions may be gradually increased from the centerportion of the first opening toward the edge of the first opening. Thiswill be applied to other embodiments and modified examples thereof thatwill be described later.

FIG. 7 is a schematic cross-sectional view of a part of a display deviceaccording to an embodiment, and for example, around the first opening inthe first inorganic insulating layer. In the display device, the unevensurface 160 a of the organic material layer 160 may have a plurality ofprotrusions in the second direction (+x direction) crossing the firstdirection (+y direction) as described above. Here, a height h1 from theupper surface of the substrate 100 to the protrusions at the centerportion of the first opening is greater than a height h2 from the uppersurface of the substrate 100 to the protrusions at the other portion inthe first opening.

As described above with reference to FIG. 1, the substrate 100 of thedisplay device is bent about the first bending axis 1BAX extending inthe first direction (+y direction). Accordingly, the substrate 100, theorganic material layer 160, and the first conductive layer 215 c arebent at the first bending area 1BA, and at this time, the largesttensile stress may be applied to the first conductive layer 215 c at thecenter portion of the first bending area 1BA, that is, at the centerportion of the first opening. Therefore, by increasing the height h1from the upper surface of the substrate 100 to the protrusions at thecenter portion of the first opening to be greater than the height h2from the upper surface of the substrate 100 to the protrusions at theother portion in the first opening, the surface area of the uppersurface on the organic material layer 160 at the center portion of thefirst opening and the surface area of the upper and lower surfaces ofthe first conductive layer 215 c at the center portion of the firstopening may be relatively greater than that of the other portion in thefirst opening. The large surface area on the upper surface of theorganic material layer 160 and the upper and lower surfaces of the firstconductive layer 215 c may denote a large deformation margin forreducing the tensile stress caused by the bending of the substrate 100.Here, a point where the height h1 from the upper surface of thesubstrate 100 to the protrusions is changed to the height h2 may belocated within the first bending area 1BA.

In other portion of the first opening than the center portion or theportion adjacent to the edge in the first opening, the height from theupper surface of the substrate 100 to the protrusions may be differentfrom the height h1 or the height h2. Moreover, the height from the uppersurface of the substrate 100 to the protrusions may be gradually reducedfrom the center portion of the first opening toward the edge of thefirst opening. This will be applied to other embodiments and modifiedexamples thereof that will be described later.

As shown in FIG. 8 schematically illustrating a part of a display deviceaccording to an embodiment, examples shown in FIGS. 6 and 7 may beapplied simultaneously to the display device.

For example, the distance d1 between the adjacent protrusions from amongthe protrusions at the center portion of the first opening is less thanthe distance d2 between the protrusions at the other portion in thefirst opening, and at the same time, the height h1 from the uppersurface to the protrusions at the center portion of the first openingmay be greater than the height h2 from the upper surface of thesubstrate 100 to the protrusions at the other portion in the firstopening. As such, increasing in the surface area of the upper surface ofthe organic material layer 160 at the center portion of the firstopening and the surface area of the upper and lower surface of the firstconductive layer 215 c at the center portion of the first opening may bemaximized so that the surface areas of the above layers at the centerportion in the first opening may be relatively greater than that of theother portion. The large surface area on the upper surface of theorganic material layer 160 and the upper and lower surfaces of the firstconductive layer 215 c may denote a large deformation margin forreducing the tensile stress caused by the bending of the substrate 100.In this case, the heights of the protrusions or the distances among theprotrusions may be changed gradually. Here, a point where the distanced1 between the protrusions is changed to the distance d2 may be locatedwithin the first bending area 1BA.

FIG. 9 is a schematic cross-sectional view of a part of a display deviceaccording to an embodiment, and for example, around the first opening ofthe first inorganic insulating layer. In the display device, the unevensurface 160 a of the organic material layer 160 may have a plurality ofprotrusions in the second direction (+x direction) crossing the firstdirection (+y direction). Here, a distance d2 between adjacentprotrusions from among the protrusions adjacent to the inner sidesurface of the first opening may be less than a distance d1 between theadjacent protrusions at the other portion in the first opening.

As described above with reference to FIG. 1, the substrate 100 of thedisplay device is bent about the first bending axis 1BAX extending inthe first direction (+y direction). Accordingly, the substrate 100, theorganic material layer 160, and the first conductive layer 215 c arebent at the first bending area 1BA, and at this time, the tensile stressmay be applied to the organic material layer 160 and the firstconductive layer 215 c. For example, since the buffer layer 110, thegate insulating layer 120, and/or the interlayer insulating layer 130referred to as the first inorganic insulating layer including theinorganic material have the first opening, the first inorganicinsulating layer does not exist in the first bending area 1BA. However,a part of the organic material layer 160, which is adjacent to the innerside surface of the first opening, is in contact with the firstinorganic insulating layer or adjacent to the first inorganic insulatinglayer, and thus, the part of the organic material layer 160 may beaffected by the first inorganic insulating layer having a relativelygreater hardness, and accordingly, may be likely to be damaged due tothe tensile stress.

Therefore, by reducing the distance d2 between the protrusions at theportion adjacent to the inner side surface of the first opening to beless than the distance d1 between the protrusions at the other portionin the first opening, a surface area of the upper surface of the organicmaterial layer 160 at the portion adjacent to the inner side surface ofthe first opening and a surface area of the upper and lower surfaces ofthe first conductive layer 215 c at the portion adjacent to the innerside surface of the first opening may be relatively greater than that atthe other portion of the first opening. The large surface area on theupper surface of the organic material layer 160 and the upper and lowersurfaces of the first conductive layer 215 c may denote a largedeformation margin for reducing the tensile stress caused by the bendingof the substrate 100. Here, a point where the distance d1 between theprotrusions is changed to the distance d2 may be located within thefirst bending area 1BA.

In other portion of the first opening than the center portion or theportion adjacent to the edge in the first opening, the distance betweenthe adjacent protrusions may be different from the distance d1 or thedistance d2. Moreover, the distance between the adjacent protrusionsfrom among the protrusions may be gradually reduced from the centerportion of the first opening toward the edge of the first opening.

A display device according to an embodiment may have a structure towhich examples illustrated in FIGS. 6 and 9 are both applied. Forexample, a distance between the adjacent protrusions at the centerportion of the first opening and a distance between the adjacentprotrusions at the portion adjacent to the inner side surface of thefirst opening may be less than the distance d2 between the adjacentprotrusions at the other portion in the first opening.

FIG. 10 is a schematic cross-sectional view of a part of a displaydevice according to an embodiment, and for example, around the firstopening of the first inorganic insulating layer. In the display device,the uneven surface 160 a of the organic material layer 160 may have aplurality of protrusions in the second direction (+x direction) crossingthe first direction (+y direction) as described above. Here, the heighth2 from the upper surface of the substrate 100 to the plurality ofprotrusions at the portion adjacent to the inner side surface of thefirst opening may be greater than the height h1 from the upper surfaceof the substrate 100 to the protrusions at the other portion in thefirst opening.

As described above with reference to FIG. 1, the substrate 100 of thedisplay device is bent about the first bending axis 1BAX extending inthe first direction (+y direction). Accordingly, the substrate 100, theorganic material layer 160, and the first conductive layer 215 c arebent at the first bending area 1BA, and at this time, the tensile stressmay be applied to the organic material layer 160 and the firstconductive layer 215 c. For example, since the buffer layer 110, thegate insulating layer 120, and/or the interlayer insulating layer 130referred to as the first inorganic insulating layer including theinorganic material have the first opening, the first inorganicinsulating layer does not exist in the first bending area 1BA. However,a part of the organic material layer 160, which is adjacent to the innerside surface of the first opening, is in contact with the firstinorganic insulating layer or adjacent to the first inorganic insulatinglayer, and thus, the part of the organic material layer 160 may beaffected by the first inorganic insulating layer having a relativelygreater hardness, and accordingly, may be likely to be damaged due tothe tensile stress.

Therefore, by setting the height h2 from the upper surface of thesubstrate 100 to the protrusions at the portion adjacent to the innerside surface of the first opening to be greater than the height h1 fromthe upper surface of the substrate 100 to the protrusions at the otherportion in the first opening, a surface area of the upper surface of theorganic material layer 160 at the portion adjacent to the inner sidesurface of the first opening and a surface area of the upper and lowersurfaces of the first conductive layer 215 c at the portion adjacent tothe inner side surface of the first opening may be relatively greaterthan that at the other portion of the first opening. The large surfacearea on the upper surface of the organic material layer 160 and theupper and lower surfaces of the first conductive layer 215 c may denotea large deformation margin for reducing the tensile stress caused by thebending of the substrate 100. Here, a point where the height h1 from theupper surface of the substrate 100 to the protrusions is changed to theheight h2 may be located within the first bending area 1BA.

In other portion of the first opening than the center portion or theportion adjacent to the edge in the first opening, the height from theupper surface of the substrate 100 to the protrusions may be differentfrom the height h1 or the height h2. Moreover, the height from the uppersurface of the substrate 100 to the protrusions may be graduallyincreased from the center portion of the first opening toward the edgeof the first opening. This will be applied to other embodiments andmodified examples thereof that will be described later.

A display device according to an embodiment may have a structure towhich examples illustrated in FIGS. 7 and 10 are both applied. Forexample, the height from the upper surface of the substrate 100 at thecenter portion of the first opening and the height from the uppersurface of the substrate 100 to the protrusions at the portion adjacentto the inner side surface of the first opening may be greater than theheight from the upper surface of the substrate 100 to the protrusions atthe other portion in the first opening.

In addition, as shown in FIG. 11 schematically illustrating a part of adisplay device according to an embodiment, the structures illustrated inFIGS. 9 and 10 may be both applied. For example, the distance d2 betweenthe adjacent protrusions at the portion adjacent to the inner sidesurface of the first opening is less than the distance d1 between theadjacent protrusions at the other portion in the first opening, andmoreover, the height h2 from the upper surface of the substrate 100 tothe protrusions at the portion adjacent to the inner side surface of thefirst opening may be greater than the height h1 from the upper surfaceof the substrate 100 to the protrusions at the other portion in thefirst opening. As such, increasing in the surface area of the uppersurface of the organic material layer 160 at the center portion of thefirst opening and the surface area of the upper and lower surface of thefirst conductive layer 215 c at the portion adjacent to the inner sidesurface of the opening may be maximized so that the surface areas of theabove layers at the portion adjacent to the inner side surface of thefirst opening may be relatively greater than that of the other portion.The large surface area on the upper surface of the organic materiallayer 160 and the upper and lower surfaces of the first conductive layer215 c may denote a large deformation margin for reducing the tensilestress caused by the bending of the substrate 100. In this case, theheights of the protrusions or the distances among the protrusions may bechanged gradually.

FIG. 12 is a schematic cross-sectional view of a part of a displaydevice according to an embodiment. As shown in FIG. 12, the SNL 600includes an uneven surface 600 a on at least a part of an upper surfacethereof. The uneven surface 600 a may correspond to at least the firstbending area 1BA, or may have a greater area than that of the firstbending area 1BA. Here, the uneven surface 600 a of the SNL 600 may havea shape corresponding to that of the uneven surface 160 a of the organicmaterial layer 160.

As described above, the SNL 600 may adjust a location of the stressneutral plane in the stack structure including the substrate 100, thefirst conductive layer 215 c, and the SNL 600. Therefore, the SNL 600may allow the stress neutral plane to be located around the firstconductive layer 215 c so as to reduce the tensile stress applied to thefirst conductive layer 215 c. Here, as shown in FIG. 12, since theuneven surface 600 a of the SNL 600 has the shape corresponding to thatof the uneven surface 160 a of the organic material layer 160, thestress neutral plane may be exactly located on the first conductivelayer 215 c having a shape corresponding to the uneven surface 160 a ofthe organic material layer 160. As such, the tensile stress that isapplied to the first conductive layer 215 c when the substrate 100 isbent at the first bending area 1BA may be reduced so as to prevent orreduce occurrence of defects in the first conductive layer 215 c.

The SNL 600 is formed of an organic material, and may be formed byvarious methods.

For example, as shown in FIG. 13, a first portion 601 extending in ay-axis direction along with an edge of the substrate 100 so as tocorrespond to a first protrusion that is one of the protrusions on theuneven surface 160 a of the organic material layer 160 is formed by aninkjet printing method, a jetting method, or a dotting method, and then,ultraviolet (UV) rays are irradiated onto the first portion 601 toharden the first portion 601. In addition, as shown in FIG. 14, a secondportion 602 extending in the y-axis direction along with the edge of thesubstrate to correspond to a second protrusion that is adjacent to thefirst protrusion from among the protrusions of the uneven surface 160 aof the organic material layer 160 is formed, and then, UV rays may beirradiated to the second portion 602 to harden the second portion 602.Here, a contact portion between the first portion 601 and the secondportion 602 is a concave portion, and the first portion 601 and thesecond portion 602 have convex portions at center portions thereof. Whenthe first and second portions 601 and 602 are formed, the centerportions of the first and second portions 601 and 602 are convex due tocharacteristics of the organic material included in the first and secondportions 601 and 602. By repeatedly performing the above processes, theuneven surface 600 a of the SNL 600 may correspond to the uneven surface160 a of the organic material layer 160 as shown in FIG. 15. However,unlike the example shown in FIG. 15, there may be no boundary betweenthe first portion and the second portion because the first and secondportions are formed by using the same organic material.

Otherwise, an organic material for forming the SNL 600 is located on thefirst conductive layer 215 c so as to at least correspond to the firstbending area 1BA, and a mold M having a lower surface corresponding tothe uneven surface 160 a of the organic material layer 160 may contactthe organic material for forming the SNL 600 as shown in FIG. 16. In theabove state, the UV rays are irradiated to the organic material forforming the SNL 600 to harden the organic material, and then, the mold Mis removed. Thus, the uneven surface 600 a of the SNL 600 may correspondto the uneven surface 160 a of the organic material layer 160. Ifnecessary, the UV rays are irradiated onto the organic material forforming the SNL 600 to firstly harden the organic material beforecontacting the mold M with the organic material for forming the SNL 600and after that, the lower surface of the mold M contacts the organicmaterial for forming the SNL 600. Then, the UV rays are irradiated againto the organic material for forming the SNL 600 to secondarily hardenthe organic material, and then, the mold M may be removed.

FIGS. 13 to 16, as well as FIG. 12, schematically illustrate the displaydevice according to the embodiment, and thus, thicknesses of thecomponents may be exaggerated or simplified for convenience ofdescription, and this is the same in the one or more embodiments andmodified examples thereof that will be described later.

Although the uneven surface 600 a of the SNL 600 may preciselycorrespond to the uneven surface 160 a of the organic material layer 160as shown in FIG. 12, the uneven surface 600 a of the SNL 600 may roughlycorrespond to the uneven surface 160 a of the organic material layer 160as shown in FIG. 17 that is a schematic cross-sectional view of adisplay device according to an embodiment.

For example, as shown in FIG. 17, an interval between the protrusions onthe uneven surface 600 a of the SNL 600 may be integer-times, e.g.,twice, greater than that of the uneven surface 160 a of the organicmaterial layer 160. In this case, all of the protrusions on the unevensurface 600 a of the SNL 600 correspond to at least some of theprotrusions on the uneven surface 160 a of the organic material layer160, and thus, the tensile stress applied to the first conductive layer215 c during bending the substrate 100 at the first bending area 1BA maybe reduced. Accordingly, occurrence of defects in the first conductivelayer 215 c may be reduced or prevented. On the contrary, the intervalbetween the protrusions on the uneven surface 160 a of the organicmaterial layer 160 may be integer-times greater than that of theprotrusions on the uneven surface 600 a of the SNL 600. In this case,all of the protrusions on the uneven surface 160 a of the organicmaterial layer 160 correspond to at least some of the protrusions on theuneven surface 600 a of the SNL 600, and thus, the tensile stressapplied to the first conductive layer 215 c during bending the substrate100 at the first bending area 1BA may be reduced. Accordingly,occurrence of defects in the first conductive layer 215 c may be reducedor prevented.

In addition, the upper surface of the planarization layer 140 may beflat as shown in FIG. 12, or may have an uneven surface 140 a as shownin FIG. 18 that is a schematic cross-sectional view of a part of adisplay device according to an embodiment. A method of forming theuneven surface 140 a on the upper surface of the planarization layer 140may be the same as/similar to that of forming the uneven surface 160 aon the upper surface of the organic material layer 160.

The structure of the SNL 600 described above with reference to FIGS. 12to 18 may be applied to the display devices according to the abovedescribed embodiments and other embodiments that will be describedbelow.

So far, the first inorganic insulating layer is described to have theopening, but one or more embodiments are not limited thereto. Forexample, the first inorganic insulating layer may not include the firstopening that penetrates completely through the first inorganicinsulating layer, but may include a first groove at a locationcorresponding to the first bending area 1BA. FIG. 19 is a schematiccross-sectional view of a part of a display device according to anembodiment.

As shown in FIG. 19, the buffer layer 110 may be continuously formedthroughout the first area 1A, the first bending area 1BA, and the secondarea 2A. In addition, the gate insulating layer 120 includes the opening120 a corresponding to the first bending area 1BA, and the interlayerinsulating layer 130 also includes the opening 130 a corresponding tothe first bending area 1BA. Accordingly, the first inorganic insulatinglayer that includes the buffer layer 110, the gate insulating layer 120,and the interlayer insulating layer 130 may be described to have thefirst groove corresponding to the first bending area 1BA. The firstinorganic insulating layer may include a first groove of a differenttype. For example, the upper surface of the buffer layer 110 (in +zdirection) may be partially removed, or a lower surface of the gateinsulating layer 120 (in −z direction) may not be removed.

That the first groove corresponds to the first bending area 1BA maydenote that the first groove overlaps with the first bending area 1BA.Here, an area of the first groove may be greater than that of the firstbending area 1BA. To do this, a width GW of the first groove is shown tobe greater than a width of the first bending area 1BA in FIG. 19. Here,the area of the first groove may be defined as an area of the openinghaving the smallest area, between the openings 120 a and 130 a of thegate insulating layer 120 and the interlayer insulating layer 130. InFIG. 20, the area of the first groove is defined by the area of theopening 120 a in the gate insulating layer 120.

In the display device, the organic material layer 160 may fill at leastpartially the first groove. In addition, the first conductive layer 215c is located on the organic material layer 160 in a region where theorganic material layer 160 is formed.

In FIG. 19, the display device is not in bent state for convenience ofdescription, but the substrate 100 in the display device according tothe embodiment is actually bent at the first bending area 1BA as shownin FIG. 1. To do this, the display device in which the substrate 100 isflat is manufactured as shown in FIG. 19, and after that, the substrate100 is bent at the first bending area 1BA so that the display device maybe in a state shown in FIG. 1. Here, when the substrate 100 is bent atthe first bending area 1BA, the tensile stress may be applied to thefirst conductive layer 215 c, but in the display device, the firstinorganic insulating layer includes the first groove corresponding tothe first bending area 1BA, and the portion of the first conductivelayer 215 c corresponding to the first bending area 1BA is located onthe organic material layer 160 that fills the first groove of the firstinorganic insulating layer at least partially. Therefore, occurrence ofa crack in the portion of the first conductive layer 215 c located onthe organic material layer 160, wherein the portion corresponds to thefirst bending area 1BA, may be prevented, or a possibility of generatingthe crack may be reduced.

Also, the above description about the case in which the first inorganicinsulating layer includes the first opening may be applied to the casein which the first inorganic insulating layer has the first groove. Forexample, the organic material layer 160 may cover an inner side surfaceof the first groove. In addition, the organic material layer 160 mayhave the uneven surface 160 a at least partially on the upper surfacethereof within the first groove. In addition, the area of the unevensurface 160 a in the organic material layer 160 may be greater than thatof the first bending area 1BA, and may be less than that of the firstgroove. The above descriptions about pitches or heights of theprotrusions on the uneven surface 160 a of the organic material layerwith reference to FIGS. 6 to 10 may be also applied to the case in whichthe first inorganic insulating layer includes the first groove. Inaddition, hereinafter the case in which the first inorganic insulatinglayer includes the first opening will be described for convenience ofdescription, but the descriptions below may be applied to the case inwhich the first inorganic insulating layer includes the first groove.

FIG. 20 is a schematic cross-sectional view of a part of a displaydevice according to an embodiment. In the display device, the organicmaterial layer 160 includes a plurality of islands 160 b. The islands160 b extend in the first direction (+y direction), and are spaced apartfrom one another in the second direction (+x direction). The firstconductive layer 215 c covers the islands 160 b, and accordingly, thefirst conductive layer 215 c located on the islands 160 b has an uppersurface corresponding to shapes of the islands 160 b. Therefore, asurface area of the upper surface of the first conductive layer 215 c(+z direction) is increased.

During the manufacturing processes, the substrate 100 is bent at thefirst bending area 1BA, and then, the tensile stress may be applied tothe first conductive layer 215 c. Accordingly, when the upper surfaceand/or the lower surface of the first conductive layer 215 c may havethe shape corresponding to the islands 160 b of the organic materiallayer 160, the amount of the tensile stress applied to the firstconductive layer 215 c may be reduced. That is, the tensile stress thatmay generate during the bending process may be reduced throughdeformation of the islands 160 b of the organic material layer 160having a relatively less strength. Here, the shape of the firstconductive layer 215 c that has an uneven shape at least before thebending process is deformed to correspond to the shape of the organicmaterial layer 160 that has been deformed due to the bending process,and thus, defects such as disconnection may be effectively preventedfrom occurring in the first conductive layer 215 c.

Since the first conductive layer 215 c is located on the organicmaterial layer 160, the lower surface of the first conductive layer 215c corresponds to the islands 160 b of the organic material layer 160.However, the upper surface of the first conductive layer 215 may havethe uneven surface, but the uneven surface may be independently formedfrom the islands 160 b of the organic material layer 160.

For example, a conductive material layer is formed on the organicmaterial layer 160, and a photoresist is applied onto the conductivematerial layer. Then, the photoresist is developed varying an exposureamount according to locations on the photoresist by using a slit mask ora half-tone mask, and accordingly, exposed conductive material layer isetched and the photoresist is removed to form the first conductive layer215 c. Since the exposure amount varies depending on the locations ofthe photoresist by using the slit mask or the half-tone mask, theconductive material layer has an etching degree that varies depending onlocations thereof. Therefore, the uneven surface may be artificiallyformed on the upper surface of the first conductive layer 215 c in theabove manner, and in this case, the uneven surface of the upper surfaceof the first conductive layer 215 c may have a shape that does notcorrespond to the islands 160 b of the organic material layer 160. Thiswill be applied to the embodiments and modifies examples thereof thatwill be described later. However, even if the process of artificiallyforming the uneven surface in the upper surface of the first conductivelayer 215 c is performed, the uneven surface of the first conductivelayer 215 c may correspond to the islands 160 b of the organic materiallayer 160.

FIG. 21 is a schematic cross-sectional view of a part of a displaydevice according to an embodiment, and for example, around the firstopening of the first inorganic insulating layer. In the display device,the islands 160 b of the organic material layer 160 are spaced apartfrom one another in the second direction (+x direction) as describedabove. Here, a distance d1 between adjacent islands 160 b from among theislands 160 b at the center portion of the first opening is less than adistance d2 between adjacent islands 160 b from among the islands 160 bat the other portion in the first opening.

As described above with reference to FIG. 1, the substrate 100 of thedisplay device is bent about the first bending axis 1BAX extending inthe first direction (+y direction). Accordingly, the substrate 100, theorganic material layer 160, and the first conductive layer 215 c arebent at the first bending area 1BA, and at this time, the largesttensile stress may be applied to the first conductive layer 215 c at thecenter portion of the first bending area 1BA, that is, the centerportion of the first opening. Therefore, when the distance d1 betweenthe islands 160 b at the center portion of the first opening is lessthan the distance d2 between the islands 160 b at the other portion ofthe first opening, a surface area of the islands 160 b at the centerportion of the first opening and a surface of the upper and lowersurfaces of the first conductive layer 215 c at the center portion ofthe first opening may be relatively greater than that of the otherportion in the first opening. The large surface area of the islands 160b and the upper and lower surfaces of the first conductive layer 215 cmay denote a large deformation margin for reducing the tensile stresscaused by the bending of the substrate 100.

FIG. 22 is a schematic cross-sectional view of a part of a displaydevice according to an embodiment, and for example, around the firstopening of the first inorganic insulating layer. In the display device,a height h1 from the upper surface of the substrate 100 to the islands160 b at the center portion of the first opening is greater than aheight h2 from the upper surface of the substrate 100 to the pluralityof islands 160 b at the other portion in the first opening.

As described above with reference to FIG. 1, the substrate 100 of thedisplay device is bent about the first bending axis 1BAX extending inthe first direction (+y direction). Accordingly, the substrate 100, theorganic material layer 160, and the first conductive layer 215 c arebent at the first bending area 1BA, and at this time, the largesttensile stress may be applied to the first conductive layer 215 c at thecenter portion of the first bending area 1BA, that is, the centerportion of the first opening. Therefore, when the height h1 from theupper surface of the substrate 100 to the islands 160 b at the centerportion of the first opening is greater than the height h2 from theupper surface of the substrate 100 to the islands 160 b at the otherportion in the first opening, a surface area of the islands 160 b at thecenter portion of the first opening and a surface of the upper and lowersurfaces of the first conductive layer 215 c at the center portion ofthe first opening may be relatively greater than that of the otherportion in the first opening.

In addition, as shown in FIG. 23 that is a schematic cross-sectionalview of a part of a display device according to an embodiment, thedisplay device may further include a protective film 170 for protectingthe substrate 100. The protective film 170 is a lower protective filmfor protecting a lower surface of the substrate 100, and as shown inFIG. 23, the protective film 170 may include an opening 170OP. Theopening 170OP corresponds to the first bending area 1BA, and an area ofthe opening 170OP may be greater than that of the first bending area1BA. In FIG. 23, a width of the opening 170OP is greater than the widthof the first bending area 1BA.

Since the protective film 170 protects the lower surface of thesubstrate 100, the protective film 170 may have a strength on its own.Accordingly, if the protective film 170 has a low level of flexibility,the protective film 170 may be isolated from the substrate 100 when thesubstrate 100 is bent. Therefore, as shown in FIG. 23, when theprotective film 170 includes the opening 170OP corresponding to thefirst bending area 1BA, occurrence of the isolation between theprotective film 170 and the substrate 100 may be effectively prevented.To do this, as described above, the area of the opening 170OP of theprotective film 170 needs to be greater than that of the first bendingarea 1BA.

However, considering that the protective film 170 has to protect thelower surface of the substrate 100 as much as possible, the area of theopening 170OP of the protective film 170 needs to be reduced. Therefore,the area of the opening 170OP in the protective film 170 may be greaterthan that of the first bending area 1BA, and at the same time, may besmaller than that of the first opening in the first inorganic insulatinglayer. Moreover, the area of the opening 170OP in the protective film170 may be smaller than that of the uneven surface 160 a of the organicmaterial layer 160. Thus, in FIG. 23, the width of the opening 170OP isgreater than that of the first bending area 1BA, whereas the width ofthe opening 170OP is less than the width OW of the first opening in thefirst inorganic insulating layer and the width UEW of the uneven surface160 a of the organic material layer 160. The protective film 170 havingthe above-described shape may be applied to display devices according tothe previous embodiments and the other embodiments that will bedescribed later.

If necessary, unlike the protective layer 170 shown in FIG. 23, theprotective film 170 may not cover the edge of the substrate 100. Thatis, the protective film 170 may not exist on the second area 2A.

So far, the example in which the first conductive layer 215 c is formedof the same material as the source or drain electrode 215 a or 215 b inthe TFT 210 at the same time is described above, but one or moreembodiments are not limited thereto.

For example, as shown in FIG. 24 that is a schematic cross-sectionalview of a part of a display device according to an embodiment, a touchelectrode 710 having various patterns may be located on theencapsulation layer 400 for implementing a touch sensing function. Thatis, the touch electrode 710 may be a part of touch sensing layer. Whenthe touch electrode 710 is formed, the first conductive layer 215 c maybe simultaneously formed by using the same material as that of the touchelectrode 710. Also, when a touch protective layer 720 for protectingthe touch electrode 710 is formed, a protective layer covering the firstconductive layer 215 c may be simultaneously formed. If necessary, thetouch protective layer 720 may integrally extend from the display areaDA to at least the first bending area 1BA, as shown in FIG. 24. Asdescribed above, the structure of forming the first conductive layer 215c simultaneously with the touch electrode 710 may be applied to displaydevices described above or will be described later. Unlike the aboveexample, the first conductive layer 215 c may be formed simultaneouslywith the opposite electrode 330 by using the same material as that ofthe opposite electrode 330.

In addition, the organic material layer 160 may be formed simultaneouslywith the planarization layer 140 by using the same material as that ofthe planarization layer 140. If necessary, the organic material layer160 may be formed in a separate process, without regard to theplanarization layer 140. Otherwise, as shown in FIG. 25 that is aschematic cross-sectional view of a part of a display device accordingto an embodiment, the organic material layer 160 may be formedsimultaneously with the organic encapsulation layer 420 in theencapsulation layer 400 by using the same material as that of theorganic encapsulation layer 420.

The organic material layer 160 may be formed simultaneously with otherlayers than the planarization layer 140 by using the same material. Forexample, as shown in FIG. 26 that is a schematic cross-sectional view ofa part of a display device according to an embodiment, when theinterlayer insulating layer 130 includes an organic insulating material,the organic material layer 160 may be formed simultaneously with theinterlayer insulating layer 130 by using the same material as theinterlayer insulating layer 160. Since FIG. 26 is a cross-sectionalview, the interlayer insulating layer 130 and the organic material layer160 are shown as separate layers from each other due to the contact holethrough which the first conductive layer 215 c is connected to thesecond conductive layers 213 a and 213 b. However, the interlayerinsulating layer 130 and the organic material layer 160 may beintegrally formed with each other, except the area where the contacthole is formed.

As described above, the structure in which the organic material layer160 is formed simultaneously with the interlayer insulating layer 130when the interlayer insulating layer 130 is formed of the organicmaterial, may be applied to other display devices that are describedabove or will be described later. Here, the first conductive layer 215 cmay be formed simultaneously with the touch electrode 710 by using thesame material as that of the touch electrode 710, as shown in FIG. 26.In this case, as shown in FIG. 26, the first conductive layer 215 c maycover the touch protective layer 720. Otherwise, an organic insulatinglayer in addition to the touch protective layer 720 may be necessary forimplementing the touch sensing function. For example, an additionaltouch electrode, besides the touch electrode 710, may be formed, and anorganic insulating layer may be interposed between the touch electrode710 and the additional touch electrode. In this case, the organicinsulating layer may extend to cover the first conductive layer 215 c,or a layer that is formed simultaneously with the organic insulatinglayer by using the same material as the organic insulating layer maycover the first conductive layer 215 c.

The first conductive layer 215 c may be modified variously, for example,the first conductive layer 215 c may be simultaneously formed with thesource electrode 215 a or the drain electrode 215 b, not with the touchelectrode 710. In addition, in this case, the first conductive layer 215c may be covered by the planarization layer 140 or another insulatinglayer.

So far, the case in which the first inorganic insulating layer includesthe gate insulating layer 120 that is interposed between thesemiconductor layer 211 and the gate electrode 213 is described, but oneor more embodiments are not limited thereto. For example, as shown inFIG. 27 that is a schematic cross-sectional view of a part of a displaydevice according to an embodiment, the first inorganic insulating layermay only include the buffer layer 110 that is arranged between the TFT210 and the substrate 100. In this case, the buffer layer 110 includesthe opening 110 a that may be referred to as the first opening. Inaddition, the gate insulating layer 120 may function as the organicmaterial layer 160 that is described in the previous embodiments. Thatis, the gate insulating layer 120 may include an insulating organicmaterial.

In this case, the gate insulating layer 120 may have an uneven surface120 b in at least a part of an upper surface thereof within the firstopening as shown in FIG. 27. A shape of the uneven surface 120 b of thegate insulating layer 120, and pitches or heights of a plurality ofprotrusions included in the uneven surface 120 b may adopt thedescription about the shape of the uneven surface 160 a of the organicmaterial layer 160, and the pitches and heights of the protrusions inthe uneven surface 160 a with reference to FIGS. 6 to 10. Moreover,similarly to the organic material layer 160 including the islands 160 bthat are spaced apart from one another as shown in FIG. 20, the gateinsulating layer 120 may include a plurality of islands that are spacedapart from one another, unlike the example illustrated in FIG. 27. Inthis case, the description about the pitches or heights of the islands160 b described above with reference to FIGS. 21 and 22 may be appliedto the islands of the gate insulating layer 120.

As described above, when the gate insulating layer 120 functions as theorganic material layer, the first conductive layer 215 c may be formedsimultaneously with the source electrode 215 a or the drain electrode215 b by using the same material as that of the source electrode 215 aor the drain electrode 215 b, as shown in FIG. 27. As illustrated withreference to FIGS. 24 to 26, if the touch electrode 710 of variouspatterns is located on the encapsulation layer 400 that covers the OLED300 for implementing the touch sensing function, the first conductivelayer 215 c may be simultaneously formed with the touch electrode 710 byusing the same material as the touch electrode 710.

FIG. 28 is a schematic cross-sectional view of a part of a displaydevice according to an embodiment. The display device may include a TFT210′ on the display area DA, in addition to the TFT 210. The TFT 210′may include a semiconductor layer 211′, a source electrode 215 a′, adrain electrode 215 b′, and a gate electrode 213′. Here, thesemiconductor layer 211′ may include the same material as thesemiconductor layer 211, and may be located at the same layer level asthe semiconductor layer 211. The source electrode 215 a′ and the drainelectrode 215 b′ may include the same material as that of the sourceelectrode 215 a and the drain electrode 215 b as well, and may belocated at the same layer level as that of the source electrode 215 aand the drain electrode 215 b. However, the gate electrode 213′ may belocated at a different layer level from that of the gate electrode 213.

For example, a gate insulating layer 120′ is located on the gateinsulating layer 120, and the source electrode 215 a, the drainelectrode 215 b, the source electrode 215 a′, and the drain electrode215 b′ may be located on the interlayer insulating layer 130 that coversthe gate insulating layer 120′. In addition, the gate electrode 213 islocated on the gate insulating layer 120, the gate insulating layer 120′covers the gate electrode 213, and the gate electrode 213′ may belocated on the gate insulating layer 120′. Here, the buffer layer 110and the gate insulating layer 120 respectively include the opening 110 aand the opening 120 a, and the gate insulating layer 120′ may functionas the organic material layer 160 described above with reference to theprevious embodiments. That is, the gate insulating layer 120 may includean insulating organic material.

In this case, the gate insulating layer 120′ may have an uneven surface120′a at least partially in an upper surface thereof within the firstopening, as shown in FIG. 28. A shape of the uneven surface 120′a of thegate insulating layer 120′, and pitches or heights of a plurality ofprotrusions in the uneven surface 120′a may adopt the description aboutthe shape of the uneven surface 160 a of the organic material layer 160,and the pitches or heights of the protrusions of the uneven surface 160a described above with reference to FIGS. 6 to 10. In addition,similarly to the islands 160 b that are spaced apart from one another inthe organic material layer 160 as shown in FIG. 20, the gate insulatinglayer 120′ may include a plurality of islands that are spaced apart fromone another, unlike the example shown in FIG. 28. In this case, theabove descriptions about the pitches or heights of the islands 160 bwith reference to FIGS. 21 and 22 may be applied to the islands of thegate insulating layer 120′.

In the above structure, the first conductive layer 215 c may be formedsimultaneously when the source electrode 215 a or the drain electrode215 b is formed as shown in FIG. 28. However, one or more embodimentsare not limited thereto, and the first conductive layer 215 c may beformed simultaneously when the gate electrode 213′ is formed by usingthe same material as the gate electrode 213′. Moreover, as describedabove with reference to FIGS. 24 to 26, when the touch electrode 710 ofthe various pattern for implementing the touch sensing function islocated on the encapsulation layer 400 that covers the OLED 300, thefirst conductive layer 215 c may be formed simultaneously with the touchelectrode 710 by using the same material as the touch electrode 710.

In the embodiment illustrated in FIG. 28, the interlayer insulatinglayer 130 is located on the gate insulating layer 120′ that functions asthe organic material layer, and thus, the interlayer insulating layer130 includes an opening 130 a corresponding to the first opening of thefirst inorganic insulating layer including the buffer layer 110 and thegate insulating layer 120. Such above interlayer insulating layer may bedefined as a second inorganic insulating layer and the opening 130 a maybe defined as a second opening of the second inorganic insulating layer.

FIG. 29 is a schematic cross-sectional view of a part of a displaydevice according to an embodiment. The display device is different fromthe display device illustrated in FIG. 28 in that the first conductivelayer 215 c is formed simultaneously with the gate electrode 213′ byusing the same material as the gate electrode 213′, not with the sourceelectrode 215 a or the drain electrode 215 b.

Since the gate electrode 213′ is located on the gate insulating layer120′ that covers the gate electrode 213, the first conductive layer 215c that is formed simultaneously with the gate electrode 213′ by usingthe same material as the gate electrode 213′ is located on the secondconductive layers 213 a and 213 b that are formed simultaneously withthe gate electrode 213 by using the same material as the gate electrode213 and the uneven surface 120′a of the gate insulating layer 120;including an organic material. Here, the interlayer insulating layer 130may cover a part of the first conducive layer 215 c, if necessary. Theinterlayer insulating layer 130 includes opening 130 a corresponding tothe openings 110 a and 120 a of the buffer layer 110 and the gateinsulating layer 120 so that the bending may be performed easily on thefirst bending area 1BA.

As described above, the location, the material, and the method offorming the first conductive layer 215 c may be modified variously.

FIG. 30 is a schematic cross-sectional view of a part of a displaydevice according to an embodiment. The display device of the embodimentis different from the display device described above with reference toFIG. 29 in view of further including an additional conductive layer 215d on the first conductive layer 215 c. As described above, when thefirst conductive layer 215 c is formed simultaneously with the gateelectrode 213′ by using the same material as that of the gate electrode213′, the additional conductive layer 215 d may be simultaneously formedwith the source electrode 215 a or the drain electrode 215 b by usingthe same material as the source electrode 215 a or the drain electrode215 b. The additional conductive layer 215 d may be located on the firstconductive layer 215 c in the first bending area 1BA, so as to beelectrically connected to the first conductive layer 215 c.

In the display device, since the first conductive layer 215 c and theadditional conductive layer 215 d exist on the first bending area 1BA,multi-layered conductive layer structure is formed on the first bendingarea 1BA. Therefore, even when a defect such as a crack occurs in thefirst conductive layer 215 c on the first bending area 1BA, electricsignals may be transferred to the display area DA via the additionalconductive layer 215 d. Also, even if a defect such as a crack occurs inthe additional conductive layer 215 d, the electric signal may betransferred to the display area DA via the first conductive layer 215 c.

According to the above description, the organic material layer 160 isdescribed to be simultaneously formed with the gate insulating layer120, the gate insulating layer 120′, the interlayer insulating layer130, and/or the planarization layer 140. However, one or moreembodiments are not limited thereto. For example, the organic materiallayer 160 may be formed by a separate process, from the processes offorming the gate insulating layer 120, the gate insulating layer 120′,the interlayer insulating layer 130, and/or the planarization layer 140.Also, even when the gate insulating layer 120, the gate insulating layer120′, the interlayer insulating layer 130, and/or the planarizationlayer 140 include the organic material, the organic material layer 160may include a different material from those of the gate insulating layer120, the gate insulating layer 120′, the interlayer insulating layer130, and/or the planarization layer 140.

FIG. 31 is a schematic cross-sectional view of a part of a displaydevice according to an embodiment. The display device according to theembodiment is different from the display device described above withreference to FIG. 30 in that the interlayer insulating layer 130 isarranged between the first conductive layer 215 c and the additionalconductive layer 215 d. Here, since the interlayer insulating layer 130includes the insulating organic material, damages on the interlayerinsulating layer 130, the first conductive layer 215 c, and/or theadditional conductive layer 215 d due to the bending process may beprevented even when the interlayer insulating layer 130 exists in thefirst bending area 1BA.

In addition, the additional conductive layer 215 d on the interlayerinsulating layer 130 is electrically connected to the first conductivelayer 215 c under the interlayer insulating layer 130 via the contacthole in the interlayer insulating layer 130, wherein the contact hole isformed on an outer portion of the first bending area 1BA. As such, evenif the defect such as crack occurs in the first conductive layer 215 con the first bending area 1BA, the electric signal may be transferred tothe display area DA via the additional conductive layer 215 d. Also,even if the defect such as crack occurs in the additional conductivelayer 215 d, the electric signal may be transferred to the display areaDA via the first conductive layer 215 c. In addition, since theinterlayer insulating layer 130 is arranged between the first conductivelayer 215 c and the additional conductive layer 215 d, growth of thecrack occurring in one of the first conductive layer 215 c and theadditional conductive layer 215 d to the other layer may be effectivelyprevented.

In the structure illustrated with reference to FIGS. 30 and 31, a widthof the first conductive layer 215 c and a width of the additionalconductive layer 215 d in the first direction (+y direction) may bedifferent from each other. For example, the first conductive layer 215 cand the additional conductive layer 215 d may include differentmaterials from each other, and accordingly, a flexibility (elongationrate) of the material forming the first conductive layer 215 c and aflexibility (elongation rate) of the material forming the additionalconductive layer 215 d may be different from each other. A greaterflexibility (elongation rate) may denote less probability of generatingdisconnection even when the tensile stress is applied. Therefore,between the first conductive layer 215 c and the additional conductivelayer 215 d, one including a material having a relatively greaterflexibility (elongation rate) than the other may have a smaller widththan the other.

FIG. 32 is a schematic cross-sectional view of a part of a displaydevice according to an embodiment. The display device according to theembodiment is different from the display device described above withreference to FIG. 2 in view of further including a protective layer 180covering the TFT 210. The protective layer 180 may cover a lower layerof the TFT 210, e.g., the interlayer insulating layer 210, on a portionwhere the TFT 210 does not exist. The protective layer 180 may includean inorganic material such as silicon nitride, silicon oxide, and/orsilicon oxynitride, and may have a single-layered structure or amulti-layered structure. As described above, since the buffer layer 110,the gate insulating layer 120, and the interlayer insulating layer 130including the inorganic material may be referred to as the inorganicinsulating layer, the protective layer 180 including the inorganicmaterial may be referred to as an additional inorganic insulating layer.

As described above, the protective layer 180, e.g., the additionalinorganic insulating layer, may cover most of the first area 1A and thesecond 2A on the substrate 100 and include an additional opening 180 acorresponding to the first bending area 1BA. Here, that the additionalopening 180 a corresponds to the first bending area 1BA may denote thatthe additional opening 180 a overlaps with the first bending area 1BA.Here, an area of the additional opening 180 a may be greater than thatof the first bending area 1BA. To do this, in FIG. 32, a width of theadditional opening 180 a is shown to be greater than that of the firstbending area 1BA.

As described above, the display device shown in FIG. 32 is not in a bentstate, but the display device is actually bent, that is, the substrate100 is bent at the first bending area 1BA as shown in FIG. 1. To dothis, the display device is manufactured so that the substrate 100 isflat as shown in FIG. 32, and after that, the substrate 100 is bent atthe first bending area 1BA so that the display device has the shapeshown in FIG. 1.

If the protective layer 180 does not include the additional opening 180a and is located on the first conductive layer 215 c in the firstbending area 1BA, the tensile stress may be applied to the protectivelayer 180 in the first bending area 1BA during bending the substrate 100at the first bending area 1BA, and then, a crack may occur in theprotective layer 180. When the crack occurs in the protective layer 180,the crack may extend to the first conductive layer 215 c covered by theprotective layer 180, and accordingly, a possibility of generatingdefects such as disconnection in the first conductive layer 215 c may begreatly increased.

However, according to the display device of the embodiment, theprotective layer 180, that is, the additional inorganic insulatinglayer, includes the additional opening 180 a corresponding to the firstbending area 1BA. Therefore, damages on the first conductive layer 215 cmay be prevented or reduced.

FIG. 33 is a schematic cross-sectional of the display device of FIG. 32taken along the first bending axis 1BAX in the first bending area 1BA.Based on FIG. 1, FIG. 33 may be understood to show a part of thecross-section of the display device on the first bending area 1BA, takenalong a plane that is in parallel with an xy plane and includes thefirst bending axis 1BAX. As shown in FIG. 33, the protective layer 180may not exist within the first bending area 1BA. In FIG. 33, there seemto be a plurality of first conductive layers 215 c, and thus, thedisplay device may include a plurality of first conductive layers 215 cthat are wires extending in a direction. As described above, theprotective layer 180 may not exist in the first bending area 1BA, but isnot limited thereto.

For example, as shown in FIG. 34 that is a schematic cross-sectionalview of a part of a display device according to an embodiment, theprotective layer 180 may be formed in the first bending area 1BA. Thatis, that the protective layer 180, e.g., the additional inorganicinsulating layer, has the additional opening 180 a corresponding to thefirst bending area 1BA denote that the additional opening 180 acorresponds to the first bending area 1BA, and it is not limited to thatthe protective layer 180 should not exist on the first bending area 1BA.

Here, the additional opening 180 a may correspond to the firstconductive layer 215 c within the first bending area 1BA, as shown inFIG. 34. For example, the additional opening 180 a may overlap with thefirst conductive layer 215 c in the first bending area 1BA. In FIG. 34,the additional opening 180 a overlaps with most of the upper surface ofthe first conductive layer 215 c, so that the protective layer 180 maycover an edge of the first conductive layer 215 c.

In the display device according to the embodiment, most of the uppersurface of the first conductive layer 215 c may not be covered by theprotective layer 180. Therefore, even when the tensile stress is appliedto the protective layer 180 in the first bending area 1BA during thesubstrate 100 is being bent at the first bending area 1BA and the crackmay occur in the protective layer 180, a possibility that the crackextends to the first conductive layer 215 c and causes damage on thefirst conductive layer 215 c may be reduced. In the first bending area1BA, the organic material layer 160 is located under the protectivelayer 180, and the planarization layer 140 including the organicmaterial is located on the protective layer 180. Therefore, even if thecrack occurs in the protective layer 180 in the first bending area 1BA,extending of the crack toward the upper and/or lower portion of theprotective layer 180 may be prevented.

One or more embodiments are not limited to the above example, that is,as shown in FIG. 35 that is a schematic cross-sectional view of a partof a display device according to an embodiment, an area of theadditional opening 180 a may be greater than an area of the uppersurface of the first conductive layer 215 c within the first bendingarea 1BA, so that the first conductive layer 215 c may not be covered bythe protective layer 180 within the first bending area 1BA. In thiscase, as shown in FIG. 35, the protective layer 180 may cover the uppersurface of the organic material layer 160 at least partially on an outerportion of the first conductive layer 215 c, within the first bendingarea 1BA.

As shown in FIG. 36 that is a schematic cross-sectional view of a partof a display device according to an embodiment, an upper conductivelayer 215 c′ that is located at different layer level from the firstconductive layer 215 c may exist in the first bending area 1BA. Theupper conductive layer 215 c′ may be a wire extending in a directionthat is the same as or similar to that of the first conductive layer 215c. In addition, a protective layer may have a dual-layered structureincluding a first protective layer 181 including an inorganic materialand a second protective layer 182 including an inorganic material. Thefirst protective layer 181 and the second protective layer 182 includethe same material as that of the protective layer 180. In FIG. 36, thefirst conductive layer 215 c and the first protective layer 181 arecovered by a first planarization layer 141, and the upper conductivelayer 215 c′ and the second protective layer 182 are located on thefirst planarization layer 141. In addition, the upper conductive layer215 c′ and the second protective layer 182 are covered by a secondplanarization layer 142.

In the display device according to the embodiment, the first protectivelayer 181 does not cover the first conductive layer 215 c and the secondprotective layer 182 does not cover the upper conductive layer 215 c′ inthe first bending area 1BA, and thus, damage to the first conductivelayer 215 c and/or the upper conductive layer 215 c′ due to the bendingmay be prevented or reduced. However, similarly to the above descriptionwith reference to FIG. 34, the first protective layer 181 may cover anedge of the first conductive layer 215 c and the second protective layer182 may cover an edge of the upper conductive layer 215 c′. In addition,as shown in FIG. 37 that is a schematic cross-sectional view of a partof a display device according to an embodiment, the first protectivelayer 181 and the second protective layer 182 may not exist within thefirst bending area 1BA.

In addition, as shown in FIG. 38 that is a schematic cross-sectionalview of a part of a display device according to an embodiment, theadditional opening 180 a of the protective layer 180 that is theadditional inorganic insulating layer does not only correspond to thefirst bending area 1BA, but may also have an area that is greater thanthat of the first opening in the inorganic insulating layer. In FIG. 38,a width AOW of the additional opening 180 a is greater than the width OWof the first opening. As described above, although the display device ofFIG. 8 is described not to be bent, the display device according to theembodiment is actually bent, that is, the substrate 100 is bent at thefirst bending area 1BA. When the substrate 100 is bent at the firstbending area 1BA, a relatively larger tensile stress may be applied tothe inorganic insulating layer located at a higher level than to theinorganic insulating layer located at a lower level. Therefore, when thearea of the additional opening 180 a of the protective layer 180 issufficiently greater than that of the first opening in the inorganicinsulating layer, damage to the protective layer 180 located above theinorganic insulating layer may be prevented or reduced. However, one ormore embodiments are not limited thereto, that is, the area of theadditional opening 180 a of the protective layer 180 may be smaller thanthat of the first opening in the inorganic insulating layer as shown inFIG. 32, if necessary.

In FIGS. 32 and 38, the inner side surface of the opening 110 a in thebuffer layer 110 and the inner side surface of the opening 120 a in thegate insulating layer 120 correspond to each other, but are not limitedthereto. For example, as shown in FIG. 39 that is a schematiccross-sectional view of a part of a display device according to anembodiment, the opening 110 a in the buffer layer 110 may have an areathat is smaller than that of the opening 120 a in the gate insulatinglayer 120. In this case, the area of the first opening may be defined asan area of one having the smallest area from among the openings 110 a,120 a, and 130 a of the buffer layer 110, the gate insulating layer 120,and the interlayer insulating layer 130. Unlike the example shown inFIG. 39, the inner side surface of the opening 120 a in the gateinsulating layer 120 and the inner side surface of the opening 130 a inthe interlayer insulating layer 130 may be equal to each other.

So far, the inorganic insulating layer is described to have the opening,but one or more embodiments are not limited thereto. For example, theinorganic insulating layer may not include the first opening thatcompletely penetrates through the inorganic insulating layer at aportion corresponding to the first bending area 1BA but may include afirst groove corresponding to the first bending area 1BA. FIG. 40 is aschematic cross-sectional view of a part of a display device accordingto an embodiment, that is, showing the above example.

As shown in FIG. 40, the buffer layer 110 may be continuously formedthrough the first area 1A, the first bending area 1BA, and the secondarea 2A. In addition, the gate insulating layer 120 may have the opening120 a corresponding to the first bending area 1BA, and the interlayerinsulating layer 130 may have the opening 130 a corresponding to thefirst bending area 1BA. Accordingly, the inorganic insulating layerincluding the buffer layer 110, the gate insulating layer 120, and theinterlayer insulating layer 130 may be appreciated to have the firstgroove corresponding to the first bending area 1BA. The inorganicinsulating layer may include the first groove of various shapes. Forexample, an upper surface of the buffer layer 110 (in +z direction) maybe partially removed, but a lower surface of the gate insulating layer120 (in −z direction) may not be removed.

That the first groove corresponds to the first bending area 1BA maydenote that the first groove may overlap with the first bending area1BA. Here, an area of the first groove may be greater than that of thefirst bending area 1BA. To do this, in FIG. 4, a width GW of the firstgroove is shown to be greater than the width of the first bending area1BA. Here, the area of the first groove may be defined as an area of onehaving the smaller area, between the openings 120 a and 130 a of thegate insulating layer 120 and the interlayer insulating layer 130. InFIG. 40, the area of the first groove is defined by the area of theopening 120 a of the gate insulating layer 120.

In the display device according to the embodiment, the organic materiallayer 160 may fill at least a part of the first groove. In addition, thefirst conductive layer 215 c is located on the organic material layer160, in the region where the organic material layer 160 exists. Inaddition, the protective layer 180, that is, an additional inorganicinsulating layer, includes the additional opening 180 a corresponding tothe first bending area 1BA, and covers the first conductive layer 215 c.

In FIG. 40, the display device is not bent for convenience ofdescription, but in the display device according to the embodiment, thesubstrate 100 is actually bent at the first bending area 1BA as shown inFIG. 1. To do this, the display device is manufactured in a state thatthe substrate 100 is flat as shown in FIG. 40, and after that, thesubstrate 100 is bent at the first bending area 1BA so that the displaydevice may be in the state shown in FIG. 1.

Here, the tensile stress may be applied to the first conductive layer215 c when the substrate 100 is bent at the first bending area 1BA, butin the display device, the inorganic insulating layer includes the firstgroove on the first bending area 1BA, and the portion of the firstconductive layer 215 c, wherein the portion corresponds to the firstbending area 1BA, is located on the organic material layer 160 thatfills at least a part of the first groove in the inorganic insulatinglayer. Therefore, occurrence of crack in the first conductive layer 215c corresponding to the first bending area 1BA and located on the organicmaterial layer 160 may be prevented, or a possibility of generating thecrack may be reduced. In addition, since the protective layer 180, thatis, the additional inorganic insulating layer, includes the additionalopening 180 a corresponding to the first bending area 1BA, occurrence ofthe crack in the first conductive layer 215 c located on the organicmaterial layer 160 and corresponding to the first bending area 1BA maybe prevented or reduced. In addition, since the protective layer 180,that is, the additional inorganic insulating layer, includes theadditional opening 180 a corresponding to the first bending area 1BA,occurrence of the crack in the protective layer 180 may be prevented oreven when the crack occurs in the protective layer 180, transferring thecrack to the first conductive layer 215 c and generating defects in thefirst conductive layer 215 c may be prevented effectively.

The above descriptions about the case in which the inorganic insulatinglayer includes the first opening may be all applied to the case in whichthe inorganic insulating layer includes the first groove. For example,the structure described above with reference to FIGS. 33 to 37 may beapplied to the structure shown in FIG. 40. Hereinafter, the case inwhich the inorganic insulating layer includes the first opening will bedescribed below for convenience of description, but the descriptionsbelow may be also applied to the case in which the inorganic insulatinglayer includes the first groove.

In the above-described embodiments, the first conductive layer 215 cextends in the second direction (+x direction) and crosses the firstdirection (+y direction) in which the uneven surface 160 a in the uppersurface of the organic material layer 160 extends. A crossing angle maybe 90° as shown in FIG. 41 that is a plan view of a part of a displaydevice according to an embodiment, or may be an angle other than 90° asshown in FIG. 42. In FIGS. 41 and 42, a reference numeral GD denotes adirection in which the uneven surface 160 a in the upper surface of theorganic material layer 160 extends. When comparing with FIG. 41, FIG. 42shows that the direction in which the uneven surface 160 a in the uppersurface of the organic material layer 160 extends is inclined toward thesecond direction (+x direction), but one or more embodiments are notlimited thereto. For example, as shown in FIG. 41, the uneven surface160 a in the upper surface of the organic material layer 160 extends inthe first direction (+y direction), and the first conductive layer 215 cextends in a direction inclined with respect to the second direction (+xdirection) (e.g., a direction forming an angle of 45° with the seconddirection (+x direction)), not in the second direction (+x direction).If there are a plurality of first conductive layers 215 c, the directionin which some of the first conductive layers 215 c extend may form adifferent angle with the second direction (+x direction) from that ofthe direction in which some other of the first conductive layers 215 cextend.

In addition, FIGS. 41 and 42 show that the first conductive layer 215extends straightly in the second direction (+x direction), but one ormore embodiments are not limited thereto. For example, the firstconductive layer 215 c extends straightly in the second direction (+xdirection), and at the same time, may include a plurality of throughholes extending in +z direction. That is, at least a part of the firstconductive layer 215 c may have a plane (xy plane) that crosses thefirst direction (+y direction) and the second direction (+x direction),wherein the plane has a honeycomb shape. Otherwise, the first conductivelayer 215 c may not extend straightly in the second direction (+xdirection), but may have a zig-zag shape or a wave shape on the plane(xy plane) crossing the first direction (+y direction) and the seconddirection (+x direction).

In addition, as shown in FIGS. 41 and 42, there may be a plurality offirst conductive layers 215 c extending in the second direction (+xdirection). Here, unlike the examples shown in FIGS. 41 and 42, adistance between centers in the first conductive layers 215 c in thefirst bending area 1BA may be greater than a distance between centers ofthe first conductive layers 215 c on at least a region except the firstbending area 1BA. Accordingly, a width of each first conductive layer215 c in the first bending area 1BA in the first direction (+ydirection) may be greater than a width of each first conductive layer215 c in the first direction (+y direction) on the at least a regionexcept the first bending area 1BA. As described above, when the widthsof the first conductive layers 215 c in the first bending area 1BA areincreased, a probability of generating disconnection in the firstconductive layer 215 c due to the stress caused by the bending at thefirst bending area 1BA may be greatly reduced.

The distance between the first conductive layers 215 c on the firstbending area 1BA and the distance between the first conductive layers215 c on at least a region except the first bending area 1BA may besubstantially equal to each other. In this case, the width of the firstconductive layer 215 c in the first direction (+y direction) on thefirst bending area 1BA may be formed to be greater than that of thefirst conductive layer 215 c in the first direction (+y direction) on atleast a region except the first bending area 1BA, and thus, theprobability of generating disconnection in the first conductive layer215 c due to a stress caused by the bending at the first bending area1BA may be greatly reduced.

FIG. 43 is a schematic perspective view of a part of a display deviceaccording to an embodiment, for example, the substrate 100. In addition,FIG. 44 is a schematic plan view of the substrate 100 of FIG. 43 beforebeing bent.

Unlike the example illustrated with reference to FIG. 1, the displaydevice includes a second bending area 1BA, in addition to the firstbending area 1BA. The second bending area 2BA is located within thefirst area 1A. As the substrate 100 is bent about the first bending axis1BAX extending in the first direction (+y direction) at the firstbending area 1BA, the substrate 100 is also bent about a second bendingaxis 2BAX extending in the second direction (+x direction). Here, acorner of the substrate 100 is chamfered, wherein the corner is closestto a portion where the first bending axis 1BAX and the second bendingaxis 2BAX cross each other, and thus, the substrate 100 has a chamferedportion CP. Since the chamfered portion CP exists, the substrate 100 maybe bent not only about the first bending axis 1BAX, but also about thesecond bending axis 2BAX at the same time.

Here, a radius of curvature R1 of the first bending area 1BA may besmaller than a radius of curvature of the second bending area 2BA. Thisis understood that the substrate 100 is bent at the second bending area2BA more gently than at the first bending area 1BA. Therefore, in thesecond bending area 2BA where the substrate 100 is bent gently, thetensile stress applied to components of the display device may berelatively smaller than that applied to the components at the firstbending area 1BA. The first inorganic insulating layer as in theabove-described display device includes the first opening or the firstgroove in the first bending area 1BA, but may be continuously formedover at least a region including the second bending area 2BA in thefirst area 1A. Here, the reason why the first inorganic insulating layeris continuously formed over at least a region is that the firstinorganic insulating layer may include contact holes for electricallyconnecting conductive layers located on upper and lower portions thereofin the first area 1A. The contact holes may have circular shapes, ovalshapes, square shapes, or the like on the plan view, and the firstopening or the first groove may be shown as a rectangular shape having avery large aspect ratio in the plan view.

Although a display device does not exist within the first bending area1BA, the display device may be formed over the second bending area 2BAthat is included in the first area 1A. Accordingly, the display devicehaving an at least bent portion may be implemented. In addition, sincethe display device is bent at the second bending area 2BA, a user mayrecognize as if a peripheral area, on which images are not displayed andpads are located, has a reduced area when the user watches a displaysurface of the display device.

In addition, as described above, since the chamfered portion CP isformed, the substrate 100 may be bent about the second bending axis 2BAXcrossing the first bending axis 1BAX, as well as about the first axis1BAX, at the same time. Here, the chamfered portion CP may be rounded sothat a sharp angle may not be formed toward a center portion of thesubstrate 100, as shown in FIG. 44.

As shown in FIG. 43, the first bending area 1BA is bent about the firstbending axis 1BAX and the second bending area 2BA is bent about thesecond bending axis 2BAX, a large stress is applied a corner CN towardthe center portion of the substrate 100 in the chamfered portion CP, andthus, the substrate 100 may be torn or damaged. Therefore, in order toprevent defects from generating, the chamfered portion CP may have thecorner CN that is rounded toward the center portion of the substrate 100as shown in FIG. 44. Here, a radius of curvature at the corner CN towardthe center portion of the substrate 100 may be about 1/20 to about ⅕ ofthe radius of curvature at the first bending area 1BA, for example,1/10.

In addition, in order to prevent the large stress from being applied tothe corner CN toward the center portion of the substrate 100 when thefirst bending area 1BA is bent about the first bending axis 1BAX and thesecond bending area 2BA is bent about the second bending axis 2BAX, anend of the first bending area 1BA toward the first area 1A may be closerto the edge of the substrate 100 than an extension line of a firstcutting line 1CL of the chamfered portion CP. For example, a distancebetween the end of the first bending area 1BA toward the first area 1Aand the extension line of the first cutting line 1CL may be about 500μm.

An end of the second bending area 2BA toward the center portion of thesubstrate 100 may be closer to the edge of the substrate 100 than anextension line of a second cutting line 2CL of the chamfered portion CP.Here, as described above, since the radius of curvature R2 at the secondbending area 2BA is greater than the radius of curvature R1 at the firstbending area 1BA, the stress applied to the corner CN of the chamferedportion CP due to the bending at the second bending area 2BA is smallerthan the stress applied to the corner CN of the chamfered portion CP dueto the bending at the first bending area 1BA. Therefore, a distancebetween the end of the second bending area 2BA toward the center portionof the substrate 100 and the extension line of the second cutting line2CL may be shorter than the distance between the end of the firstbending area 1BA toward the first area 1A and the extension line of thefirst cutting line 1CL.

The above descriptions about the corner CN of the chamfered portion CPmay be applied to the other embodiments or modified examples thereof.

In FIG. 43, the display device is described to include the secondbending area 2BA, in addition to the first bending area 1BA, but is notlimited thereto. For example, as shown in FIG. 45 that is a schematicperspective view of a part of a display device according to anembodiment, a third bending area 3BA and a fourth bending area 4BA maybe provided, in addition to the first or the second bending area 1BA or2BA. In the above-described display device, it may be appreciated thatfour edges of the display device are all bent. Here, the third bendingarea 3BA and the fourth bending area 4BA may have structures that arethe same as/similar to the second bending area 2BA.

Display devices may exist in the second bending area 2BA, the thirdbending area 3BA, and the fourth bending area 4BA included in the firstarea 1A. Accordingly, the display device having four bent edges may beimplemented. In addition, since the display device is bent at the secondto fourth bending areas 2BA to 4BA, the user may recognize as if theperipheral area on which images are not displayed and pads are locatedhas been reduced, when the user sees the display device.

FIG. 46 is a schematic perspective view of a part of a display deviceaccording to an embodiment. Unlike the example shown in FIG. 45, thefirst bending area 1BA and the second area 2A may be provided in thesecond direction (+x direction), and in opposite direction (−xdirection) as well. Like the second area 2A existing in the seconddirection (+x direction), various electronic devices may be located inthe second area 2A or printed circuit boards may be electricallyconnected to the second area 2A.

As described above about the display devices according to one or moreembodiments, at least two embodiments may be applied to one displaydevice unless they are contradictory to each other. For example, theprotective film 170 of the display device according to the embodimentillustrated with reference to FIG. 23 may be applied to the displaydevice according to the embodiment illustrated with reference to FIG.32.

Aforementioned bending area may be understood as a bent area, becausethe substrate is bent in that area. However, the present invention isnot limited thereto, and thus may be applied to a flexible or bendabledisplay having the bending area.

According to one or more embodiments, a longer lifespan of the displaydevice may be guaranteed and generation of defects may be reduced duringmanufacturing the display device.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While the inventive technology has been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. A display device comprising: a substrate; a firstinorganic insulating layer over the substrate and having a first openingor groove; a first conductive layer on the first inorganic insulatinglayer; a second inorganic insulating layer having contact holes and asecond opening or groove on the first conductive layer; a first organicmaterial layer over the first opening or groove and the second openingor groove; a second conductive layer on the first organic materiallayer; and a second organic material layer on the second conductivelayer, wherein the second conductive layer extends over the firstopening or groove and the second opening or groove and electricallycontacts to the first conductive layer through the contact holes.
 2. Thedisplay device of claim 1, wherein the display device is bent at thefirst opening or groove.
 3. The display device of claim 2, furthercomprising: a third organic material layer on the second organicmaterial layer over the first opening or groove.
 4. The display deviceof claim 3, further comprising: a thin film transistor arranged over thesubstrate, wherein the thin film transistor comprises a semiconductorlayer, a source electrode, a drain electrode, and a gate electrode, andwherein the first inorganic insulating layer is arranged between thesubstrate and the gate electrode.
 5. The display device of claim 4,wherein the second inorganic insulating layer is arranged over the gateelectrode.
 6. The display device of claim 4, further comprising: anencapsulation layer comprising an inorganic encapsulation layer and anorganic encapsulation layer, wherein the encapsulation layer covers thethin film transistor.
 7. The display device of claim 6, furthercomprising: a touch electrode on the encapsulation layer.
 8. The displaydevice of claim 1, wherein a width of the second opening or groove iswider than a width of the first opening or groove.
 9. The display deviceof claim 8, further comprising: a third organic material layer on thesecond organic material layer over the first opening or groove.
 10. Thedisplay device of claim 9, further comprising: a thin film transistorarranged over the substrate, wherein the thin film transistor comprisesa semiconductor layer, a source electrode, a drain electrode, and a gateelectrode, and wherein the first inorganic insulating layer is arrangedbetween the substrate and the gate electrode.
 11. The display device ofclaim 10, wherein the second inorganic insulating layer is arranged overthe gate electrode.
 12. The display device of claim 11, furthercomprising: an encapsulation layer comprising an inorganic encapsulationlayer and an organic encapsulation layer, wherein the encapsulationlayer covers the thin film transistor.
 13. The display device of claim12, further comprising: a touch electrode on the encapsulation layer.14. A display device comprising: a substrate; a first inorganicinsulating layer over the substrate and having a first opening orgroove; a first conductive layer on the first inorganic insulatinglayer; a second inorganic insulating layer having contact holes and asecond opening or groove on the first conductive layer, wherein a widthof the second opening or groove is wider than a width of the firstopening or groove; a second conductive layer on the first organicmaterial layer; and a first organic material layer in directly contactto the second conductive layer, wherein the second conductive layerextends over the first opening or groove and the second opening orgroove and electrically contacts to the first conductive layer throughthe contact holes.
 15. The display device of claim 14, wherein thedisplay device is bent at the first opening or groove.
 16. The displaydevice of claim 14, further comprising: a second organic material layeron the first organic material layer over the first opening or groove.17. The display device of claim 14, further comprising: a thin filmtransistor arranged over the substrate, wherein the thin film transistorcomprises a semiconductor layer, a source electrode, a drain electrode,and a gate electrode, and wherein the first inorganic insulating layeris arranged between the substrate and the gate electrode.
 18. Thedisplay device of claim 17, wherein the second inorganic insulatinglayer is arranged over the gate electrode.
 19. The display device ofclaim 17, further comprising: an encapsulation layer comprising aninorganic encapsulation layer and an organic encapsulation layer,wherein the encapsulation layer covers the thin film transistor.
 20. Thedisplay device of claim 19, further comprising: a touch electrode on theencapsulation layer.
 21. The display device of claim 14, furthercomprising: a third organic material layer over the first opening orgroove and the second opening or groove, wherein the third organicmaterial layer is arranged between the substrate and the secondconductive layer.
 22. The display device of claim 17, furthercomprising: a third inorganic insulating layer under the semiconductorlayer.
 23. The display device of claim 22, wherein the third inorganicinsulating layer has a third opening or groove exposing a portion of thesubstrate.
 24. The display device of claim 22, wherein the third openingor groove has a same shape as the first opening or groove.
 25. Thedisplay device of claim 24, wherein the third organic material layerdirectly contact the portion of the substrate and the second conductivelayer.
 26. The display device of claim 25, further comprising: anencapsulation layer comprising an inorganic encapsulation layer and anorganic encapsulation layer, wherein the encapsulation layer covers thethin film transistor.
 27. The display device of claim 26, furthercomprising: a touch electrode on the encapsulation layer.